It's also added a few nice touches that I was just starting to really miss in the previous version. In particular, the cropping tool now had a grid to help you with the rule-of-thirds -- well timed, considering I just started reading through a load of tutorials on composition -- and there's not just highlight and shadow adjustments available, but also noise reduction. NR is definitely useful for my not-so-hot current camera, especially when zooming in for a crop.
You can also copy and paste adjustments from one photo to another, so if you've got a series of similar photos, you can play with one until it works and then just clone the goodness.
So far, colour me very impressed. I think this will stave off some of my pangs of desire for Lightroom or Aperture (definitely heading more towards Lightroom right now) for some considerable time.