Jay Thomas has said that his goal is to draw some of the guests away from X2 and towards another area. Tim also said he is working with Intamin, so perhaps this will be something cool. If not, and they just plan on running a car backwards, that will still be fun, and perhaps it will just be one of a few cool thing they add to the park in the next year or two.
I'm still hoping for a giant gyro-frisbee soon...MaxAir is just killer...