At last, an image workflow processing system designed from the ground up to be exactly that, and even at beta 3 very usable and highly intuitive (much more so than many other Adobe offerings).
A more cynical individual than I might surmise that Adobe's unusual decision to write for Mac first and then follow up with a Windows version was a move designed to deliver Apple's own image management system Aperture a fatal blow before it even reaches adolescence.
With Apple's offering requiring a ludicrous hardware minimum of a gig of RAM and one of a fairly short list of 128 meg minimum NVIDIA and ATI graphics cards, it really doesn't stand a chance. I can't run it on my Mac Mini, for example.
All of which is something of a shame, as two competing products aimed at the same market might cause both to evolve quicker. I just can't see Apple holding their own against such a competent onslaught.