It looks like the time to register for Adepticon 2011 is here.
They have 256 spots for the 40K championships open and they are not going to be adding any more (which makes since in an elimination format). In a couple of days they are already down to 150 open slots, so if you are thinking about going I would jump on it. Every year they sell out earlier and earlier. Last year they sold out around the end of January and the way that they have been moving they might not make it to December (or possibly November).