With subscriptions to the respective sports packages, I do get the SNY SD channel on both Dish and DirecTV. While all Mets games are blacked out on Dish, pre-games and post-games (often including the end of the games themselves) are indeed viewable here in Santa Cruz, CA. That's what I was expecting to get in HD when Dish bragged about their new 9 national RSN-HD channels.
I really don't understand why Dish would make all the other announced HD-RSNs (like Pittsburgh's Fox Sports... Pittsburgh???) available nationwide but not SNY. Hopefully DirecTV will switch to the high-def feed full time with their big HD rollout in September.
Thanks for the help in determining why I can't get Dish's SNY-HD channel 388. As usual, Dish Network "support" was absolutely worthless. "We don't have any information on these channels" and "wait and see if it ever appears" left me rolling my eyes in frustration. Then again, DirecTV's "support" is equally inept.