I have the PSP-2000 and I have to say it is a very nice little system. I don't think the new one offers enough to justify upgrading though.
I only bought my DS Lite at the start of June but its just fine for me so I won't be upgrading anytime soon. The rumour has been semi-confirmed by Nintendo bigwigs at the E3 earlier this year but theres no press release to back it up and probably won't be until around November or so. But from what they've hinted, it won't be anything more than a slightly different structure to the DS, maybe as alittle as making it slightly larger again but with widescreen's or having a new opening mechanism.
I plan on getting another PSP. About a year or so ago, I originally owned one for two weeks and then my dad and I both lost our jobs, so I returned it to the store to get the money back. I've been holding out to see if they'll be updating the browsing features. The original PSP I think handled only 2 MB of browsing memory, which meant that many websites wouldn't load because it would run out of memory. I also used it to watch movies, and loved it while I had it, but I agree that the joystick hurt after a few minutes of using it. I think PSPs are terrific though. Fun technology, that's for sure! J.
^ I believe the PSP Slim (PSP-2000?) increased internal RAM from 32MB to 64MB to allow for better web browsing capabilities.