According to TFN, a 15-second preview of Star Wars: Rebels will air on Disney XD on Monday, Oct. 7.
It's something of a viewer-grab for Mighty Med, a new live-action show about a hospital for superheroes. The Rebels spot will air some time between 8:30 and 9:00 p.m. on Monday, during the premiere of Mighty Med. (Disney's site says that Med will have a one-hour premier, while TFN sets the Rebels spot within a half hour timeframe, so we'll see what happens with that.)
TFN also reports that the spot "will not include any actual clips from Rebels."
I'm not sure what it will include, but it's sure to be meticulously examined.
Be sure to keep an eye on my Rebels tag for coverage, some of which will be shared with Fangirlblog.