AnusNinja of SWF, who works at Gamestop, claims that his store may be getting Brawl demos in as early as next week. I called my Gamestop and all they said was they tend to have demos a few weeks before the game is released. I asked if two weeks from now sounds about right and they said most likely. So it looks like we may be getting our hands on Brawl demos a little earlier than we thought.
http://brawlcentral.com/news.php?y=2008&m=1
http://brawlcentral.com/news.php?y=2008&m=1