Here's a couple sneak peak YouTube videos on some of the new features. They look like amazing new tools for the tool box.
Painting in Adobe Photoshop CS5 Step by Step
Adobe Photoshop CS5 - PatchMatch
And it looks like CS5 will bring on HDR/Photomatix/Tone Mapping/Topaz Adjust filter. Some will love, and others will not.
Photos of The Adobe San Jose Headquarters were taken by Kelly Castro, a quality engineer on the Adobe Photoshop Lightroom Team.
Rumour has it that CS5 will finally be 64-bit for Mac users and can utilize more than 3.2 gigs of ram!