It's not actually called the PSP2 yet, the going name so far is NGP (Next Generation Portable). That being said, the specs are out, and I hear it's comparable in performance to the PS3. Skyrim will be for th PS3. It'd be interesting, to say the least, if Skyrim was for a portable system.
But it will be using small flash memory to store its games. I doubt that Skyrim would be able to fit on it, much less some of the other games for PS3 that require BluRay disks just to fit them.
You can fit as much information on flash as you can on blu-rays. And with all the games being released on flash it will also drive the price of whatever format they choose down.
Edit: Indeed you can fit a lot more onto flash than blu-rays;
http://www.sonyinsider.com/2009/08/05/sony-finalizes-backwards-compatible-memory-stick-xc-with-2tb-maximum-capacity/.
Never mind the fact the games won't be that big, but it just proves the memory isn't limited.