I voted think 4e, hope 4e. Not necessarily because I want a totally new addition to D&D. It's moreso a case of I will not buy a 3.75 edition(even if its called 4e), after buying enough 3.0 and 3.5 books to last me a lifetime, I could only see myself investing in a new edition if it changed drastically and in a direction I felt was "better" than 3.5 ie simplifying or "dumbing down" the rules. Otherwise games such as C&C and True20 give me my fix for a simpler system and I can use the 3.x library I have with them.
I am curious to see what move WotC will make as far as this is concerned. I see advantages and disadvantages to either choice. I also doubt a new edition will be anywhere near as popular as 3.x. With the resurgence of interest in older editions, simpler variants, fans who stayed with 3.0 and those who choose to stay with 3.5, It seems as if the market is destined to fracture more than it already has.
I think one reason it didn't with 3.5 is because the OGL was still new and games such as True20, C&C, OSRIC, OGL games etc. hadn't been produced yet(basically a limited market). Each of these variants may not sell as much as D&D, but they do affect it's market base.
The above reasoning is why I see WotC's best option is trying to simplify and make the game appeal to a mainstream audience, they need a new customer base and rehashing of the old isn't going to do that. The game needs to have lower entry-level requirements, and mass-market appeal if it will continue to prosper.