Philly has signed veteran Jeff Garcia who to his credit performed quite well with Philly a few years back when McNabb was hurt. So now there is 4 possible people that can play the position. Although Reid hasn't said it yet AFAIK with this acquisition I'd have to say that pretty much seals the deal that Kolb will get his first start next Sunday and Vick will not be starting any games in the near future.
Assuming Kolb plays well I'd expect to see him until McNabb returns. I hope he does well, now is the time for him to step up if he expects to play in the NFL. Imagine the pressure he's under, this game could seal the fate of his career.