Sat through a CS4 demo and the new features were extremely impressive. InDesign finally has a Preflight Option that monitors the formatting and spacing. Photoshop now has a ton of pre-made workspaces, found out the animation (image ready) is only available in photoshop extended. Photoshop also now has a full section on non-destructive imaging... there is a new workspace for adjustments that now adjusts the image using vector mask, so at anytime you can delete that vector mask and not ruin the intial image. (contrast, level, brightness, etc) But if you use the original file menu image > adjustments... it will be the old way and destruct the image. Also a great feature in Photoshop CS4 is the tabbed imaging... just like in dreamweaver, photoshop now has tabs for multiple images opened in photoshop.
I will keep ya up to date on the new features as I discover them myself.