This is the instance grind method planned by my group, which is a Prot warrior (me), Warlock (Maalakai), Mage (Cheesycraft), Ret paladin (Scrubz), and Resto shaman (Vallkor)
Use it at your own risk. Posting by popular demand!
Instance grinding to 80 outline
The path we're taking has been planned with a few things in mind:
Decently high mob density, due to AOE heavy group
Quick instances (no longer than 15 minutes, ideally 12)
No complicated mechanics (brains can safely shut down)
Familiar with the places!
We tested this on the Beta rather extensively, and what we ended up with was
Utgarde Keep until 74
The Temple of Ahn'kahet until 77
Halls of Stone until 80
However, there are a few little things here and there that are useful to know. Here's a bit of a guide.
Utgarde Keep
First, get the quest on your way in, it's from an NPC outside, kind of on the "2nd level". Dwarf npc, Defender Mordun
http://www.wowhead.com/?npc=24111 Simple quests, you gather 5 weapon racks that are all over the instance, and the other is to kill the end boss.
As for how to do the instance efficiently, well it's very linear. Here's an old video of one of our speed runs with quite a few errors, it can easily be improved upon to 12 minutes total, which is the ideal time because you can't run more than 5 instances an hour anyway.
http://files.filefront.com/PremoUtga.../fileinfo.html
Run through the place, pull 1-2 packs at a time if they're close and possible. When getting near stairwells it is a good idea to not pull extra packs together, because a 4 pull + another 4 pull + a patrol of 2-3 can easily blow you up. So, play it a bit safer near the stairwells and such which is where the patrols + extra group adds are most likely to happen.
The only thing to watch out for that the mobs do is
Bolthorn's Rune of Flame which the runecasters use. It's dispellable, so either shield slam, or some other class, can take it off. Otherwise, if they're left up, you're going to be taking a lot of extra damage. There's another shield that absorbs 50k damage,
Njord's Rune of Protection
also dispellable, which you will basically have to do if you want to kill the mob in a timely manner.
The first boss puts ice tombs on a random player, you have to attack the tomb itself to free the player. The second boss just falls over, the first one you kill will resurrect after you kill it once, so you end up having to kill both of them but tanking them both for the full duration. The final guy has a really damaging PBAOE attack in his undead form that you want to back out for, but with enough DPS in the group you can kill him before he uses it or finishes casting it.
Azjol-Nerub
Azjol-Nerub is a bad instance to grind because the mob density is not high at all. However, doing it once for the quests will make it worth it. So, head to the area (conveniently, it is right next door to the next instance), which is in Dragonblight.
The first boss has 3 captains that each have their own adds. They can be pulled individually and are easy, the boss himself is easy and has a minor AOE request. The second boss, Hadronox, you will probably have to go down and meet halfway, rather than wait for him to fight his way up, you'll be swarmed by adds if you do it this way but it will be a very quick fight. The final boss has "phases" where he submerges and thus you are forced to deal with adds before you can kill him again.
http://www.mmo-champion.com/index.php?page=793
That page has all the minor relevent information, which is basically: Pick up the 2 quests, do the easy, quick instance, and turn the quests in. Then, go to...
Ahn'Kahet: The Old Kingdom
Right next door to Azjol-Nerub is Ahn'Kahet. Grab the two quests outside the zone. AK is a great instance because it has an incredibly dense mob population.
As soon as you zone in, you don't see much. But you head forward a bit and then on either side of the first "door", and maybe pathing around, are a bunch of spiders. Pull both packs and AOE them down.
A bit further in the instance there's lots of packs like that, as you can see in attached screenshots there's pretty much spiders everywhere you look in conveniently sized packs right next to others that you can pull together, in addition to lots of roaming packs.
These packs will have two basic types of mobs, and a third standard "grunt" mob. There's the uh, web-shooter ones, which will randomly root people, which aren't that much of an annoyance, and the Spell Flingers. The spell flingers have a
sweet ability on a 6 second cast (which is approximately Forever) that does 50% of the target's health in damage. This equates to 20k damage if you reflect it, or probably 6-8k damage to your tank (if your tank is in DPS gear). As a warrior tank, reflecting this is a huge amount of extra damage. As anything else, you want to interrupt their spell, but quite frankly they take so long to cast it that if the mob isn't dead by then or if you haven't accidentally stunned it or interrupted it by now, I don't know what to say.
You'll soon be at the first boss, who also goes into "phases". He goes immune, as well as all of the AOE adds he summons. An elite comes out, which is weak and does basically nothing. You have to kill the elite in order to take down the immunities. This repeats every 25% HP of the boss.
Next is a big open area with some patrolling big undead giant guys and some AOE packs. You need to go up these web ramps to the right and hit some buttons. After hitting both buttons (there's elite packs at the top, btw), the next boss is "released". You'll be able to engage him.
The boss does nothing special but periodically "crowd controls" someone in the group, damaging them over time, but otherwise doing nothing. You basically shoot at it until it dies. You then move on through the little tiny tunnel that is unlocked after his death.
After exiting that tunnel you're looking out into a room with a MASSIVE amount of mobs. There's 3-4 packs of elites mere feet apart and patrollers, too. To your left as you're looking out is a path down to an area with some mobs for one of the quests outside. It's quite a hoof, and from what I hear, the drop item isn't for the whole group, so you end up wasting a lot of time down there. Skip that whole damn area for now.
The big courtyard is basically a circle, but the "back" part of it is a boss. The boss is annoying and the events take an eternity, with no way to speed it up. Thus, SKIP THE BOSS. You do not need to clear that back area and engage the boss to move on and kill the final boss of the zone. Skipping that boss will shave off a huge amount of time and greatly speed up your leveling rate.
So you're basically going to enter and go in a big "U" path, you can clear from the top of the stairs heading up to the boss's area, since there is a pack up there you can pull, and then backtrack and go around to the new area. None of the mobs do anything noteworthy, you stab them, they die.
There's another web ramp heading up. The final boss is kind of cool, his "phase" splits (they use repetitive phase changes on like every boss now) involve you phase shifting yourself and seeing your party members hostile to you. You have to kill them all to release yourself; everyone else has the same goal, and you're each in your own "realm". Classes do generic things, mages fireball, warriors shield slam, bash, etc. Nothing too threatening, everyone is more than capable of dealing with the rest of the group. If you do take too long to finish off your hostile group in your realm, you shift back in naturally and the rest of your real group can kill them for you. You suck.
Anyway, after a few rounds of that the boss dies and you run past him and out the exit, ending up outside the portal ready to zone in and do it again.
Halls of Stone
btw picture shamelessly cropped and edited from mmo-champion. bibi, consider this your reimbursement for that one thing that one time
After hitting 77 in Ahn'Kahet, you will go to Dalaran and train your Flying mount skill, at the Helipad area. Congratulations. Now fly to Storm Peaks and go to Ulduar in the north. Halls of Stone is the instance on the left.
Mobs in Halls of Stone hurt way more than the past 2 instances, so a tank wearing actual tanking gear is going to be necessary especially when things get messy. The mobs don't do anything special but they inflict pain. Kill big things first, like the big giants, when you inevitably aggro one while fighting other stuff. Warriors can reflect many of the spells from the dwarf mobs.
About halfway through the instance you'll come across a smallish area with two packs of mobs milling about, and another patrol that mopes around in there too. It is extremely easy to pull one pack and accidentally get all three. Infact, the chances of you getting all 3 packs is right under 100%, especially when careless. So what you should do is anticipate that happening, plan for it, and do it. Use all of your cooldowns for the 8 pull, it will hurt, no matter how you cut it. Creative use of timers, aoe taunts, reflects, stuns, and generally not being bad will let you take the 8 pull on without casualties, which is the goal when power leveling. You have been warned!
First boss you'll encounter, Maiden of Grief. You can stand in the black cloud she puts down and burn her down, because the cloud's damage is really minimal, and prevents the CC she does.
Then backtrack, and skip the Brann Bronzebeard area (marked by the X), because the Brann Bronzebeard event takes like 15 minutes by itself slowing down the run. Yes, you miss out on 2 "bosses" this way, but it is SIGNIFICANTLY FASTER.
Go into the cave area and aoe/kill the stuff, it's all trivial, Krystallus uses Ground Smash like gruul, which was a complicated and difficult mechanic, then dies. You hop down, zone out, and repeat. Do this until you're numb, and 80.
You win!