Every PSP is basically the same, except that the revisions past the 1000 cost less to produce, and use less power (and have a smaller battery). The 2000 and beyond also have extra memory that the browser, etc. can use.
You will NEVER, EVER see a PSP with a touchscreen or 2nd analog. NEVER. If such a beast ever came into existance, it wouldn't be a PSP -- it'd be a PSP2.
Seriously. What kind of fools would a publisher have to be to support a touchscreen or dual analog for a PSP game, when only a small fraction of the users could even use it?
PSP-4000 would just be the latest revision of the hardware. Its not a big deal. The 2000 and 3000 are practically identical, you know. I applaud Sony for smartly improving their hardware production costs throughout their product lifetimes. I laugh at people who honestly believe the model numbers are a big deal, outside of the Go. The slim redesign wasn't really even that important, unless you used the browser alot.
You don't hear people whining about the DS Lite, DSi, or DS XL redesigns. I don't see how this is different.
