I have a friend that works for Lego and stocks stores for the whole Dallas area and a lot of those are Wal-Marts. I asked him about Kinect supplies at Wal-Marts and he said they had a pretty fair amount. I looked at my Wal-Mart yesterday and all I saw were two 4GB bundles but the Best Buy still had loads of them.
As for the Kinect itself, I'm loving the Hell out of it. I can't wait until more of the dashboard is included in the Kinect Hub (mainly Netflix) because the voice controls are just cool. I'm a little dissapointed with how they implemented voice and Kinect controls in Zune, it's really hard to browse or find what exactly you want.
For the games, Your Shape tore me up yesterday and I've had a blast with Kinect Adventures. I had a few friends over Friday night and we played it for hours and all had a great time.
As for space, I'm a little surprised my living room is still a little small since my office is even smaller and it works fine there.