Burnout: Crash is a downloadable game. With that bit of information and the word "Crash" in the title, it's not too tough to figure out what this XBLA/PSN release might be. And your assumptions are (mostly) right. Burnout: Crash takes the fantastic Crash mode from games like Burnout 3: Takedown and spins it out into its own game. Considering the puzzle-like nature of the mode, it's well-suited for a short-session downloadable game. But Burnout: Crash doesn't just yank material from the previous games and repackage it. Criterion's building an all-new game that lets you look at your crashes from an all-new perspective.
The other piece of the Burnout: Crash puzzle should come into focus once you know that it's a top-down game. It looks sort of similar to the old Grand Theft Auto games, though this is a polygonal game. The basic idea is the same, though. You'll select a car, with heavier cars like the B-Team Van creating bigger explosions than the lighter, faster models, and you'll drive into traffic. Once you've crashed, you can guide your car around in mid-air using aftertouch, which is something of a Burnout staple. This lets you curve and glide around as you attempt to slam into as many different cars as possible. Should you find yourself at a standstill, you can execute a crashbreaker--again, nothing you Burnout aficionados would be unfamiliar with--to pop back up and keep moving. A meter on the screen, governs the use of your crashbreaker, but the idea is that you'll be able to blow up every five or ten seconds, keeping the action moving.