Some time between now and December. You can keep you eye in the other threads dedicated to the additions of HD locals for rumored exact dates; just remember to take rumors with a grain of salt:
Danwink, your ears must have been burning; LOL! Just 2 - 3 days after your inquiry you get an official announcement; sweet! Sorry nothing specific other than the already rumored "by the end of 2006", but at least now you know you are on that official list!