I said that I would post the Beauty and the Beast/Pride and Prejudice crossover trailer this week, and here it is. Actually, the trailer of which I speak is the second one here. The first one is one I encountered while searching for the second one.
Now, I'm not a huge fan of the 2005 version of Pride and Prejudice, but its theatrical trailer does mix quite nicely with Beauty and the Beast. The first trailer is P&P with B&B audio, and the second is B&B with P&P audio.