Sadly, I was in the middle of work when the G+ Hangout occurred, but the trailer is out for everyone to view at:
The recording of the G+ Hangout where the trailer premiered is also available. Lot of discussion over how they translated various aspects of the book to the big screen (and their hope that fans like the changes/concessions that had to be made):
For those who don't want to watch all 32 minutes, some highlights:
Official Website: http://www.if-sentinel.com/
Book readers will be sure to see one change already (from what I hear, it was with Card's blessing).
In fact, book lovers will know that Card has repeatedly shot down effort after effort to make a movie out of this book, but gave this one his blessing, so here's hoping!
Also, it's easy to make fun of, but that's a lot of Academy Award Nominees.