It seems very possible to be an artificially created shortage, clearing out RROD hardware or another reason mentioned above. When I first started hearing of the possibilities of a shortage I made a note to pay attention to what I see In stores locally. I live in New York City and noticed that although you can find a few Arcade bundles in most stores, I have yet to see an Elite model and probably saw maybe a handful of premiums a week. This weekend all I spotted was Arcades in places like EB, Best Buy, Target, Toys'r'us and a few other places (yea I have been doing a lot of shopping recently, hehe).
Oh by the way, I'm new to this site but I have been entering as a guest for a while. I found the forums interesting and just had to join, hehe.