The rumors were true! Comcast cable in my area has added TNT in HD. There was no announcement or anything, I just flipped through the channel listings and voila, there it was -- "TNTHD". I'm pretty psyched since I want to watch the NBA playoffs in HD and some of the best games (as well as the best commentators) are on TNT. Looks like I won't be switching to satellite anytime soon.
ABC is being stupid and doesn't appear to be showing all games in HD (at least the opening game of the Nets-Heat series that's on right now is not), but between ESPN and TNT it looks like the playoffs are gonna be worth watching!