I have emailed Marc Lumpkin and Michael Schwimmer about this and have not even received the courtesy of a reply back.
If I read the press release from the NBA correctly, the NBA TV - HD stuff will be carried by IN HD which neither Dish Network or DirecTV carry.
If this is true there really is no need for the HD Special Events Channel, which has not shown a special event since the Cart Race this summer (which came from HDNet)