I agree with others who claim that Ulduar will bring a chunk of that back. I do want to bring up something else that is probably lowering the raid numbers and causing people to drop out and that is that we have 3 raids (Naxx, OS, EoE) on 10 man and 25 man of which to get your BiS from (not including VoA). I’ve usually seen the dragons done on one day and Naxx on another. So this equals up to 4 days of raiding on one character a week to attend all raids.
I can barely afford to casually raid on my Warlock every now and then when my main is committed to raiding that schedule without getting burned out, yet the game also demands I do dungeons and level alts and maybe a little pvp to help keep the game alive? Oh and of course I can’t forget some dailies.
I am looking forward to Ulduar because I imagine it will be a nice break from 4-5 raiding nights a week to 2-3.