I don't believe sony is going to release the psp2 anytime soon. They are just starting to profit with the ps3 and judging by sony's past efforts it would take a lot of money to produce a successor to the psp on the scale that they would like it to be on.
Their tagline for the psp when it was released was that it made the home console experience mobile since it's graphics was comparable to their home console (ps2) at the time. Imagine how much it would cost to make a system that has graphics comparable to their ps3 system and I'm sure sony would like to implement some form of 3d, motion control, and introduce some new media format to play games on like they usually do with their systems dvd, umd, blu ray, etc.
I don't think we are going to see a psp2 until late 2012 at the earliest.
