The Snipers update is what I'm really hanging out for, the Medic, Pyro and Heavy are (or were) among my least played classes, and will probably return that way once all the updates are out.
I'd like to see the Sniper get an en-bloc clip for his rifle, so he could fire off 3-5 shots more rapidly than standard, and having to reload after ejecting the entire clip. For extra balance they could not remove crits or something, I dunno.