Here in NJ, this year I've gained TNT-HD, ESPN2-HD and UHD. We'll also be getting MHD and an HD Special Events channel on 11/15. However with the addition of those two channels, we'll also be losing INHD2 which seems like it'll be discontinued soon, so it's not that big of a deal. Also, here they now carry all the HD sports from the RSNs in the area.
Not too bad for this year. I'm still hopeful for HDNET/HDNET Movies and National Geographic HD among others. If your market has MHD, ESPN2-HD and UHD, then I doubt that you'll see much in terms of any additional additions of national HD channels. But of course things could change.