Judging from what I can see, it's really not working.
As a 4e player, I see a combination of backward steps to legacy mechanics and kind of a craven approach to 4e concepts like minor actions and the "bloodied" condition which are couched in walls of text instead of just being called out. For example, Wizards in the recent playtest had Encounter spells. They weren't called that, but that's what they were. Healing Word? A minor action. Not called that, but that's what it was. It seems clear to me that they're not making the game for me. Mind you - this is fine. I have my games already, and I don't need WotC's blessing.
Oldschool players I've communicated with generally seem to have liked the first packet pretty well, but think it's getting overly complicated and moving too far in a 3e/4e direction.
And I've seen a good many 3e players lamenting that it's too much like 4e. Which just goes to show.
The honest truth is, I think, that there's enough kinds of D&D games now targeted to their audiences that the best Next can hope for is to be everyone's second-favorite edition. Which is fine, I suppose, but not something I can really get excited about.
-O