I agree. Crab (swerve) drives will most definitely be effective this year.
Mecanum drives will also be effective, because they are both able to get up the bumps and move with extreme maneuverability and moderate speed. The one downfall is that they have to be dead perpendicular to the ramp, or they will just drive sideways along it.
I think the best drive trains will be those built specifically for this game, such as a drive like this one:
http://www.youtube.com/watch?v=xby0SOphLUg