One consistent comment I've seen from players over the years is that they like casters, but, after a time, start wanting to have a LOT fewer options. I know as a DM, I refuse to use caster monsters. I just won't do it. They're too complicated and nowhere near worth the effort to use them for me. Now, as soon as I see a monster with a spell list, I just turn the page. 3-5 at wills or once a day powers? Ok, I can live with that. Anything more? Hard nope.
So, yeah, I hope that we can get a far, far simpler caster class for the next edition. Three spells - one for attacking targets, one for doing something to lots of targets and one for doing stuff out of combat. The effects of those three spells are expanded by level. Done.