You know, I just don't see that much to get too excited about. This looks like a standard Adobe release with incremental features; I don't see anything that stands out like, say, adjustment layers or smart objects.
Smoother panning and zooming and fluid canvas rotation
This could potentially be good. Unless it helps with multi-gig files, however, there's currently only a negligible middle ground of images where panning is an issue for me.
Adjustments panel
So it's a panel instead of a popup window. Big deal. I did see some better image interactivity in the animation, so that might be useful.
Masks panel
Great for comping, probably not great for final retouching.
Content-Aware Scaling
This looks like a fun "toy" but I can't imagine that the results are production quality. Possibly useful for comping.
Auto-blending of images
Again, a fun toy, but possibly useful for comping.
Auto-alignment of layers
Potentially useful. About once a year.
Efficient file management with Adobe Bridge CS4
Bridge. Probably useful for some people.
Extended depth of field
Again, potentially useful, about once a year.
Improved Adobe Photoshop Lightroom workflow
I don't use LR so I'm not qualified to comment here.
Better raw image processing
Good thing.?
Industry-leading color correction
Updated burn and dodge. Probably good.
More powerful printing options
I can't remember the last time I printed directly from PS.
File display options
This, actually, will probably end up being more useful to me than anything else I've seen. Depending, of course, on how it's implemented.