The main goal of the Pathfinder RPG isn't to reinvent the game; it's to keep the rules in print so that Paizo can continue producing Adventure Paths and sourcebooks and game material we're producing. With the 3.5 core books out of print now, they'll eventually become more and more difficult to find, and that's not a good place to be in for a company that mostly produces sourcebooks and adventures for that system. So we decided to take a stab at taking the game in the next step along one possible evolutionary path.
The end goal, in my mind, is to create a core rules set that allows us to continue building Adventure Paths and supplements in the same way we have been for the past 18 months or so for Pathfinder. Anyone who's looked through those products has a pretty good idea (whether they know it or not) what direction we're trying to guide the Pathfinder RPG in. At the same point, we're taking our own experience with the game over the past several years, feedback from customers over the past several years (from both Pathfinder and Dungeon/Dragon magazine), and feedback from our tens of thousands of playtesters in order to inform our decisions on what needs fixing, what needs adjustment, and what should not be changed.
It's easy, alas, to look at the playtest forums and get overwhelmed. It's a little overwhelming to us, that's for sure; a LOT of people have a LOT to say. But in the end, the Pathfinder RPG is going to be the best game it can be at supporting the style of Adventure Path Paizo produces... be they Pathfinder Adventure Paths, Dungeon Magazine Adventure Paths, or whatever.