This is the Mercedes ESF 2009 Concept, scheduled to be officially revealed next week, it represents everything Mercedes knows about safety. Early details reveal airbags being used as emergency brakes. Wait, what?
Looking at these images, it appears that there's an airbag underneath the 2010 Mercedes S400 Hybrid-based vehicle that works along with Mercedes' Pre Safe Brakes, which are essentially an electronic crumple zone, actuating the full braking force when forward-looking radar detects that a collision will occur in .6 seconds. Those are already in use on the 2010 Mercedes E-Class sedan. The airbag is designed to complement that system, increasing the overall braking ability in these emergency situations by adding friction with the ground and raising the front of the car to compensate for brake dive. Since the system only actuates when a collision is absolutely unavoidable - .6 seconds is too quick for a human to react effectively - it doesn't compromise your ability to take evasive action or avoid the crash altogether.