For me, it's obvious that Paizo should stick with 3.5 for now then move to it's own RPG down the road. The 2 rpg groups I know doesn't intend to switch to 4th edition, I'm the only one who's a little bit interrested.
If Paizo stick's with 3.5, I will be more interrested to continue purchasing products since I know I may eventually convince one of the 2 groups to play in Paizo's world. If they switch to 4th edition, I might just go to Wizards directly since they will offer character creation, dm tools, online content, etc.
I'm intrigued by the ''3.75 edition''. We could use the community to suggest adjustments to 3.5 edition without changing completly the game. It's funny, but I feel I will be part of something bigger, the creation of another RPG, it's cool in a way.