This is hot from the Sony E3 keynote, courtesy of Joystiq:
Kaz: "We are introducing the world to the evolution of the PSP ... What I'm holding is the newest version of the PSP, which will be available in September. It's not too different, it still has UMD and the same screen, but once you have it in your hand, youll see the difference. It's 33% lighter, 19% slimmer, and the battery is much improved."
So - there you go. I'll post more as soon as I know more.
UPDATE: Yeah - there's more. Much, much more....
11:48AM PDT - "It can also output high quality video. You could hook it up to your Bravia HDTV, so everyone can only your PSP. You see, this is a trailer for Spider-Man 2, which is out on Blu-ray from Sony Home Entertainment. So now, I press the display button, and as you see it's now playing on the flat screen behind me."
11:49AM PDT - "You can control what you're seeing, I'll pause it, get rid of the menu, etc. If you want the video back on your PSP, push the display button again and it's back on your PSP. You can play games, videos, show photos, all of that on a tv screen or your PSP. With DLNA, you can also access the files on your PC at home via your PSP. This sparks the imagination, and encourages developers and players alike to think beyond the norm. As you can see it comes in piano black, but there are some additional colors that are coming to North America, which Jack will show off in a moment."
So - smaller unit, better battery, video out and custom colors. And - price is $199. Sounds like a real winner to me. The only question I have is the video out. I've seen some screenshots of the new unit, and I don't see a video out jack. I wonder if they're using the USB out - if so, I wonder if it will work with the original PSP. (I'm hoping it will, anyway.)
UPDATE 2: No pics yet, but the websites are reporting that the video out is via a new connector, not USB. So - no easy upgrade for the original PSPs. Check the video on T3.co.uk for more details.