Yeah, I've heard the same thing as @Pennybug Cullen (about the airing of the first trailer at the 2011 MTV awards). It's extremely likely, however, don't get your hopes up too much, just in case. Although, I'm pretty sure everyone (including me!) will anyway, haha.
This years Comic Con will also feature footage from Breaking Dawn: Part 1. This has been confirmed in the details of the event, which Alison blogged about recently.
But don't fret! I'm sure we'll get some more official images (like for Valentine's Day, perhaps? I mean, after all, Bill Condon did release photos on Thanksgiving and Christmas. Maybe he will do the same thing with other special holidays, etc.?). Although, I don't think we will get any promotional posters till after the trailer, unfortunately.
*Sigh* Such a long wait! But ah well, at least I will be keeping plenty busy till then.