Yet another reboot of D&D is afoot. The rapidity of this reboot after the 4e release is quite revealing in my opinion. If 4e were doing well in the marketplace, I don’t believe a total rewrite would be contemplated, much less be in full execution.
The rumors of the “D&D Next” version are that it is abandoning many of the key 4e concepts that make 4e what it is. Those rumors also suggest a return to a more traditional model of spellcasters vs combat classes.
It will be interesting to see what finally emerges from the playtesting.
My guess is it won’t look much like the current 4e game.