Yea, the guild Im in is really having trouble getting 20 people together for a raid. We, somehow, managed to get 40 people for a BWL run. And TBH it was our best run, even though we have ~10 new guys in the raid. The new 41 point talents have really made raiding easier (better heals, greater DPS and some funky tanking talents). On the flip side, we have a hard time finding Tanks and healers, since all they have all respec'ed to DPS. On the Chrommie fight, the healers were crying about how hard it was keeping a DPS warrior alive.
However, our GM has stated a few times on our forums that those who make the effort to show up for raids now will be the first on the list when it comes to raiding in the expansion. However this hasnt stopped some from showing us the finger when we ask for their help in getting a raid started. I think they will be looking for a new guild come TBC. . .