Is there going to be a new PSP between 09-11

Chances are, No.

Sony only made the newest PSP because they were upset that people could still hack the psp 2000. So they installed a chip in the new psp-3000 that makes it currently "unhackable". Then they realeased it.
Since they fixed the hacking, they have no new reason to release a new PSP for a while, until the hackers find a way around the chip, and/or sony finds somthing new to add to the PSP