Now, Matticus is actually pretty gung-ho about things-- he says not to wipe unless you're down to your last healer and you've only got one rez left. I agree that there are times when soulstones should be popped (if we have enough locks, we'll usually soulstone our main healer, and so if aggro ever gets lost, he pops right back up again), but if you're on the first attempt of the day, there's nothing wrong with saving a few rezzes and repair payments. Especially in a place like Gruul's Lair on High King Maulgar, where it's easy to get out when things go south, there's no reason to fight when two tanks drop on a bad pull. Just run, save the money, and come back when HKM has reset.
But Matticus is dead on about what happens after a wipe is actually called.
If you're DPS, get to a place out of the boss' aggro range, easily reachable by healers, and stand there. That's it. When your guildies say "die in a good place," they mean it, because there's nothing more annoying than having to search around for someone's corpse because they tried to run away when a wipe was called.
In fact, most tanks and melee DPS have it easy-- on a big wipe, they usually die within aggro range of the boss, and they usually die first. So if you're a tank who goes down early, don't wait for a rez-- release and start running back. Just as you get back, the healers should have enough mana built back up to start buffing, and things can get started again right away.
And Matticus has it right about what happens after that, too: always make it very clear who's rezzing and when. If you do have more than one rez, you don't want to waste one, so everyone who can self-rez should be waiting for a call from the raidleader on who gets up. And we've talked about rezzing order before-- healers should come up first, then DPS, and then melee (though melee should have been running back from the beginning).
Nobody wants to wipe, but staying coordinated and organized, even after things go wrong, can help your guild to get right back to where you want to be-- downing the boss.