Sony executives Jack Tretton and Kaz Hirai have just presented a new, updated PSP at Sony's E3 Press Conference. The unit is 33% lighter and 19% thinner with a "much improved" battery - and it still has UMD (apparently).
The demonstration by Kaz included video output from the PSP to a high-def Bravia TV. It's not clear at this time if this is a feature exclusive to the new PSP or if it's functionality that can be added to your existing units.
Update: a Sony press release has confirmed that video-out is only through the new "video-out port", so existing PSPs will miss out on this feature.
Kaz also showed the PSP using DNLA to access media files on a local PC, this is exactly the same as the functionality recently added to the PS3 via a firmware update.
The video output mode of the PSP opens up the possibility of accessing your movie files anywhere using RemotePlay via your PS3 and displaying them on TV at your mate's house. This is almost certainly the future!
The updated PSP will be available in the standard "Piano Black" colour, as well as "Ice Silver" and some other colours in North America in September. No dates for the rest of the world yet, nor any pricing information.