I would love to see a more time/space themed arcane with actual mana management. Right now it feels like Mana Adept is itself the very enemy of the specc. Before mastery was added I thought Arcane was all about unstable raw arcane energy, then when Mana Adept popped up I changed my mind and thought "ohh its about control of pure mana". But right now it feels like the two concepts fight with each other creating an abomination specc with no real purpose, boring gameplay, minimal animations and disturbingly awful quality in general.
I believe more spells should be added in every specc for mage in order to become interesting again. All the other casters seem to have evolved over the years while mages are still the guys in the robes simply throwing weak looking bolts of elements. I don't see a master of the arcane when I stand next to other casters , I just see a boring scholar while the others all seem to have a mastery over whatever each one of them is doing.