In my opinion, the same classes will be in demand... if anything, they'll be in more demand than normal. I suspect most people will 2-3 box and attempt to kill off-the-path names.
For guild play and raiding it is always clerics that define how much splitting or raids you can fill. If you're looking to hunt named, necros will be the top pick.
clerics, bards, rangers, tanks (maybe not SK as DT kill steals will be king for boss farming) Any class that cant plant their as at a boss spawn for hours will be rare. Top played will be Enc, Dru, Monk, Nec, Sham, Wiz... while wiz isnt a good farmer is it second best as kill stealing boss