Matt Soell has posted an article at Bungie.net about the Halo Winter Season tournament being run by a collection of players who felt that there was a wider audience for Halo tourneys than the one served by the recent Halo National Championships.
The Winter Season is being held at iGames locations across North America, and will consist of a series of four-man single-elimination tournaments.
There's a nice and detailed Q&A with Jester from the Psyjnir Complex there about the genesis of the tournament, be sure to check it out.