Sadly, if Pathfinder goes 4th edition I'd have to bid Pathfinder adieu. I subscribed to Pathfinder because I wanted to support Paizo after WotC pulled the plug on Dungeon & Dragon.
I won't be supporting WotC from this point onward (unless my group utterly insists on going over to 4th edition... which I'm hoping won't be the case) and, as such, have no interest in picking up 4th edition.
I understand that Paizo has to go with the flow and publish materials for the game system that the majority of its customers are playing... though that would leave me behind.
Truth be told, I'd LOVE to see Paizo use the 3.5 SRD and OGL to create the best damn version of D&D (under some other title of course) to ever see the light of day (or florescent light of some nerd lair, as the case would probably be). Yes, they'd be biting the hand that fed them BUT, if the game took off that would rock!!!!
WotC is biting the hands that fed them and they'd get their just desserts if 4th edition utterly failed.