Going by the accompanying illustrations, the newest revision—model number PSP-3000—appears virtually indistinguishable from the most recently released version of the PSP hardware, the Slim and Lite PSP-2000.
The PSP-3000 hardware still makes use of the system's proprietary UMD media, and incorporates 802.11b Wi-Fi functionality similar to previous hardware iterations.
During a roundtable discussion at this year's E3, Sony Computer Entertainment America CEO Jack Tretton stated that further hardware revisions would be aimed at securing the device and lowering manufacturing costs. Any substantial changes in the PSP-3000 will likely be internal, focused on preventing would-be pirates from cracking the oft-exploited handheld.
Sony has yet to make an official announcement for the hardware, but will likely reveal more information in the near future.
So it's mostly a DRM (pardon the bad analogy) update then.