I skipped a couple of pages (haha, I know, I knock on people for it, but I don't have a lot of time right now) but in regards to the xboxs popping up on ebay, it's not because of the walmart deal.
It is because of this.
http://arstechnica.com/gaming/news/2009/11/cheap-to-good-home-used-360-pirated-games-slightly-banned.ars