Ok, Lori just called me in to see a commercial she described as "sad" and "painful." Shows Marty McFly crossing under the wire as the lightning strikes and the Delorean disappearing, leaving only the fire trails on the ground. Doc Brown turns to the screen and says "Great scott! I forgot to tell Marty to get DirecTV!" The logo appears and he voices "TV from Space!"
Ticked me off for several reasons... one, it was indeed both sad and painful. (Further research shows that Bob Gale and Robert Zemeckis gave their approval. That makes it even more sad.)
Second, this was the 1955 Doc Brown realizing he hadn't told the 1985 Marty McFly to get DirecTV. I'm pretty sure that DirecTV didn't exist in either of those time periods. DirecTV was still called USSB until the mid-to-late '90s, wasn't it?
And according to BTTF.com (honestly, I didn't know this existed, perhaps I'm not as much of a geek as I thought), you can expect Shatner and others to reprise their roles to encourage you to get DirecTV. Sigh. More info...