Uh, I would guess that "brought to you by" is just in the conventional "sponsored by" sense... DirecTV obvoiusly wants to have their name associated with HDTV, so sponsoring Fox's HDTV broadcasts is certainly productive. I wouldn't read too much into it, I mean, of course DirecTV is working on getting everyone's local channels to them in HD, but I don't think this is a sign that it's going to come anytime soon. DirecTV's commitment, as mentioned in their press release after the Super Bowl, is 1500 channels by 2007, which could mean 12/31/2007.
So, uh, don't hold your breath.