All I can say is, go buy one when they come out. The graphics are AMAZING, the gameplay is amazing and everything else you can think of.
Graphics: 25x better than the DS, the LCD monitor is very bright and rich in details. The large size makes it very easy to see whats going on around you.
Did I mention the LCD proves to be a very good mirror?
Sound: Very loud and clear, high quality audio. Haven't tried out the headphones that come with it yet.
Controls: The analog stick makes it very easy to move around/control; best feature of the PSP IMO.
Layout: Very sleek and professional looking. 20 total buttons on the PSP including the power and eject.
UMD (Mini Discs): kept in protective case, but the exposed portion makes it easy to get fingerprints on and etc. The disc holder seems poorly designed, doesn't seem to go with the PSP's layout. However, the PSP logo is very sexy (where the UMD's are held).
Battery Life: About 4 hours of gameplay in Ridge Racers, 2 hours on movies and not sure yet about music