People have been using Kinect to do amazing things on their PC since about three days after the peripheral was released, about three days after they were disappointed with what it could actually do. For the less adventurous and tech savvy, it would be understandable that they'd be rather excited by the prospect of an official Windows Kinect, offering all of the fun with none of the risk/hard work.
Well, avoiding that sort of thing comes at a premium with the price at Amazon currently standing at a whopping $249.99, $130 more than the version for Xbox that comes with a game. Internet experts ("I once saw a Kinect, I know what I'm talking about!") theorise that this is all about the way in which Microsoft gains money lost from the hardware back from software and a change in market when bringing this to the PC.
For the average person who just wants to play around on their PC with a Kinect, I don't think this is the solution you're looking for. Kinect for Windows will be available February 1st.