Photoshop CS3 beta is shippped with a a pre-release version of a major upgrade to Adobe Bridge, and a new tool integrated in CS3 called Adobe Device Central, which enables you to optimize your content for devices with smaller screens.
If you want to give CS3 beta a test run, you need a serial number from either Adobe Photoshop CS2, Adobe Creative Suite® 2, Adobe Creative Suite Production Studio, Adobe Design Bundle, Adobe Web Bundle or Adobe Video Bundle, and you can download Adobe Photoshop CS3 here.
I haven't gotten my hands on CS3 just yet, but you can read a review of the new features in this article. The most interesting change seems to be the new user interface with the all-new one-column toolbar, which - luckily for people that don't like change in their life - can be reverted to the standard two-column version. I'm also quite excited about the new Quick Select Tool, which makes selecting objects from a background much easier.