All that surrounds D&D (DDI, e-Dragon and Dungeon, Gleemax, PR and so on and so forth) turns me off so far.
These aside:
For the moment, 4E doesn't look worse than 3rd ed, or much better. The shorter stat block we've seen is definitely a plus, for instance, while the heavy modification of resources management in the new rules seem all but clear to me, so I'm neutral on this until I see exactly how it is modified (regarding wizard's spells, supernatural healing and the like). The prospect of 1 PHB, MM and DMG per year is a HUGE negative turn-off for me, as is the prospect of not having a complete ruleset from the get-go when compared to 3.5. I want all the classic monsters, classes, races from the start, not sprinkled throughout volumes and volumes of PHBs and MMs.
The modification in look of creatures does turn me off so far but for a few exceptions. The streamlining of the cosmology, I'm all for it, the creation of a rigid "D&D world" (i.e. points of light, Empire of Tieflings etc etc) turns me off.
I want to be able to use my 3rd ed stuff and be able to convert easily to 4E what I want to run that's been published under 3rd ed. Given the number of sources I own from 3.X, if I can't do that, I won't convert the 4E, no matter how cool the system ends up to be (that's not like there aren't already TONS of cool RPG systems out there, to tell you the truth).
All of this of course baring an absolute revelation/awe I'd feel in front of the core books when reading them for the first time, which might happen.