It's an improvement, but not enough to keep me from investing in LR 1.0 (my 30 days ends tomorrow, so this was timely)
The major improvements I see initially are....
Cropping now shows as a box in all thumbnails and the editing windows shows only the cropped image.
NR is now on a separate tab and configurable per image.
You can open the tool pallette in thumbnail view and make changes to selected groups of images right in the thumbnail view. Sweet.
It still has too many UI quirks to be really useful and still lacks straightening, vignetting and captioning. If those were included I would REALLY consider using it instead of LR.