I've been playing this game almost since launch (I came in right after the Maraudon patch, for those who remember those days.) In the course of that time, I've been a part of four different raiding guilds. I've also had to deal with pretty much every possible problem that comes along as a part of said guilds.
I've had to deal with pissy guild leaders, prima donna officers, attention whores, lackluster performance, overzealous raiders, and the often inevitable implosion/disintigration of the guild. A lot of this comes about because of the annonimity of the Internet, where people can be jerks in ways they wouldn't face-to-face.
But we put up with it, because we want raid content. We wanted to kill Ragnaros. We wanted to farm Nefarian. We wanted phat lootz, like Ashkandi and Tier pieces and whatever else.
TBC changed the dynamic somewhat by lowering the maximum raid size from 40 to 25. Fewer people to get pissy about raiding, the more stable guilds would be. Less dead weight, etc. Well, things didn't really change all that much, so now in Wrath, you're going to be able to raid with as few as 10 in every raid instance.
We've been putting this concept to the test in Ordo by hitting TBC 10-man content with our little guild. We don't have 10. We have 8, and one of them is still leveling to 70. Technically, we're tearing through Kara and ZA with only 7.
And we're kicking serious ass. Our first run last week cleared Kara of all bosses save Netherspite (and he is so not worth it.) We also took out 3 of the initial bosses in ZA. Last night, we repeated our success, clearing Kara through Shade with only a single wipe due to a botched Curator pull.
On average, we're not overgeared with Tier 6 equipment. We have some folks with that stuff, but we also have virgin 70s with instance blues and AH greens. One of our real advantages is years of raid experience. We know these fights. We know how to beat them. And the potency given to every class in the 3.0.2 patch doesn't hurt.
We're hoping to carry this over into Wrath. Can we take Naxx with only 7 or 8? Who knows? But I'm eager to try.