Just got it. So far, I found it to be a very worthwihile upgrade from CS2, especially if user interface and workflow is of importance to you.
Some of the biggest improvements - Bridge is much better than before. It incorporates many of the Lightroom functions, integrated it seemlessly with Photoshop. I do not see any need to run LR and CS3 seperately. LR is forever doomed to the neatherworld for me
ACR is much improved with more congtrol. The ability to recover details from blown images and to add fill light to shadows is amazing. The vibrant function gives a lot more control over color, a perfect compliment to the saturation congtrol.
The layout/desktop is much more user friendly, this applies to both ACR and photoshop.
More to follow later.