What Worked

It took us eight or nine attempts to finally beat Anub'Rekhan, even though it was never a hard fight.  There was always some tiny thing that wiped us each time.  Rather than going through each attempt exhaustively, I'll simply show you what we did do in the end while describing some of the things we learned along the way.  (Truth in advertising:  The following screenshots are actually a mix of screenshots from the last three attempts, because during the rush of the fight, it wasn't possible to get good illustrative screenshots on every attempt).

We started by using an exploit to despawn the two guards.  Hey, I tell it like it is.  The reasoning for doing this was that despawning the guards merely shrinks the number of rotations down by one or two, and the raid group just wanted to get to the heart of the fight right away.  However, I think people are underestimating the challenge of the first round of the fight when you're fighting two guards at once combined with Anub'Rekhan who might successfully impale some people at a bad time.  If you do fight the Crypt Guards, make sure you keep them far away from Anub'Rekhan so that the people fighting them don't get Impaled.

Here's how the exploit works.  A hunter moves up to the middle of the room and aggros Anub'Rekhan and his guards.  When they get close to the hunter, the main tank aggros Anub'Rekhan either by proximity, shooting him, or as a pickup group I was in demonstrated, simply casting Blood Rage.  The hunter feigns death.  Anub'Rekhan is now aggroed on the main tank but the guards aren't, so they think the fight is over and despawn.  I hope that we don't despawn the guards the next time we fight Anub'Rekhan, so that we can experience what the fight is supposed to be like in its entirety.

We pulled Anub'Rekhan back to the door where we entered, which closes during the fight.  Sometimes the door opened or remained open during the fight, but we couldn't figure out how to make it happen on purpose.  Having someone stand outside and try to open the door during the fight didn't work.

Once Anub'Rekhan was pulled all the way back, the raid spread out and started dps'ing him down.  Some guides have mentioned that you should heal or dps at maximum range to avoid getting impaled, but this is wrong.  Impale seems to have a 40-yard range.  It is true that if you are a healer who is only healing ranged raidmates, you can stay out of range of the Impale attack.  However, dpsers and main tank healers have to stay in range of the Impale.  Since you have to be in range anyway, it makes no difference whether you are healing or dps'ing at 40 yards, 30 yards, or 20 yards, so you might as well spread out as best as you can to avoid having too many raid members caught by the same Impale attack.

Here is a screenshot of from earlier in the evening that shows what the Impale attack looks like.

The Impale attack sounds scary in how much damage it deals, but it's not that bad.  They happen at predictable intervals, and there's plenty of time in between each one to heal everyone back up to full.  As long as the healers keep everyone topped off, there's no reason why anyone should die from Impale.

Every 90 seconds Anub'Rekhan casts his Locust Swarm spell, so one of our raid members used a crude timer mod to give the raid a 10 second warning before Anub'Rekhan started his Locust Swarm cast.  That warning gave the melee fighters plenty of time to back out and gave the ranged attackers and healers time to move back to maximum range.  Then, when the main tank's Spell Alert showed Anub'Rekhan casting his Locust Swarm spell, the main tank called it out on teamspeak and began running along the easternmost edge of the room.  The hunter in his group turned on Aspect of the Pack to give him a burst of speed and the main tank ran along the curved edge of the room to the doorway on the opposite side from the entrance doorway.  In addition, the priest in the main tank group, who therefore also had Aspect of the Pack, ran ahead and cast shields and renews on the main tank during the run.  The rest of the raid backed out of range the moment the call came that the cast had started and everyone moved to the west side of the central platform to avoid any chance of being hit by the Locust Swarm as Anub'Rekhan passed.  If everything works perfectly, the main tank does not get hit by the Locust Swarm at all.  If everything works out OK, then he or she will get hit by one or two applications of the stacking dot.  If everything works badly, then the main tank will be hit by three or more applications and no amount of healing applied is going to save him or her.

Getting the timing down of these transitions is the biggest challenge of this encounter, and I suspect that the whole encounter will become much easier when timer and alert mods are developed specifically for it.  We had several wipes due to main tanks leaving too late (the MT gets hit by too many applications of the Locust Swarm dot), main tanks leaving too early (Anub'Rekhan hits the main tank in the back and dazes him or her just as he is about to cast Locust Swarm), hunters turning on Aspect of the Pack too early (dazes the main tank), and hunters forgetting to turn on Aspect of the Pack at all. What's more, the timing on these transitions wasn't perfect, because sometimes the crude timer mod was just off.  Despawning the guards at the beginning of the encounter may have caused some of the timings to be off, and also one time Anub'Rekhan evade bugged in a corner, which threw his timer completely off.

If a main tank gets hit by too many Locust Swarm dots, there's little you can do to save him or her (shield wall, maybe?).  On one transition, I tried to run forward to throw some heals on the main tank on the theory that I could heal myself through a couple of dots and discovered to my demise that Locust Swarm also acts as a Silence effect.

There are a couple of things you can do to make the transitions across the room easier.  First, we discovered that it was best to run along the outside edge of the room rather than along the edge of the platform.  It's a longer path, which gives the tank a couple extra seconds to keep away from Anub'Rekhan during the Locust Swarm phase.  Second, if a warlock casts Curse of Tongues on Anub'Rekhan, it takes Anub'Rekhan two extra seconds to cast Locust Swarm.

If the timing of the encounter is so touchy, why use a hunter instead of a swiftness potion?  Swiftness potions are on a two minute cooldown, so they won't be available for the second transition.  You could use a swiftness potion, then a nifty stopwatch, then another swiftness potion, but then you'd be stuck on the fourth transition (which if you don't despawn the guards, you'll probably need).  You might as well train a hunter how to time the encounter now and not worry about item cooldowns later in the fight.

There is also talk about some groups using some kind of five tank shield wall rotation, but I guess this tactic was quickly patched out, because we discovered that Anub'Rekhan was immune to taunt, making such a tank rotation unfeasible.