Do you mean the 2011 Monty Madness next May? Or a different event.
Over on the VEX forums is a thread by Smartkid with a great
Omni tutorial and discussion that you might want to look at.
He also posted the designs for their
2009-10 Omnibot The second picture in the thread shows the pods that they built for the drive base. Very fast, very powerful and they can be swapped on/off the robot.