The following is my opinion, as usual, and will probably make someone mad. So now is when I begin to worry about us. We have had one person quit the game, one person get too busy to raid until their alt was 80 then they had time again (that is what happened, coincidence or not). Now someone else wants to reroll. None of these things have ruined us or set back a lot, but you can't say this hasn't hurt the group. There are still things to be done and as long as this keeps going on they won't. We still haven't downed Sarth with a drake, we have only done 3 naxx achievements so far.
Since we had to start bringing different people or toons our naxx clear time has gone up. We cleared it one night a few weeks ago and since it's only been 3 or 4 wings, which means less time for Sarth which means less work on progressing. I realize some people are still trying to find the class spec they really enjoy and want to play, that makes sense. I'm happy that I chose to go with a moonkin, it's not perfect but I like it. This is a game, which is meant to be played for amusement, if that isn't happening something should change. I don't think anyone should play a class or spec they don't enjoy, I don't.
I kind of wish we had known the raid groups ahead of time so folks could have rolled classes that that would have made better groups (as far as comps go). I'm not real picky about what I play, any type of healer or ranged dps (not hunter, I would be a huntard) would have worked for me, not everyone is this way though. I don't think this would have prevented our current problems, but it would be easier to deal with.
I do blame Blizzard for making raiding ezmode and battlegrounds torture for casual pvpers. When you start pve at 80 you find what content you can handle, when you start in pvp you get steamrolled by the death knight parade for a few weeks, it just isn't fun and in the end not worth to a lot of people. Leveling alts > getting plowed in bgs.
So I'm left to wonder if we are just content to kill all the bosses and get purples or if we want to do all the achievements and hard modes out there. The way we are waffling we won't get them done. I've given up on the them for this round, here's to hoping we have the attention span and class make up we need to push through Uludar and all the challenges it has. My goal was to kill all raid bosses and we are well on our way, which I'm loving. We have potental to a lot more than that, whether we will or not remains to be seen. That's all