Okay, so here is a crazy thought I had...
If you did a 4WD in the same configuration as a omni-wheel drive...
...(like this) (In the same fashion as "The Pre"

)
|= Chassis Perimeter
// = Wheels
. = space filler
___________
|//...........\\|
|................|
|................|
|................|
|\\...........//|
Would the low amount of friction on the wheels allow
the robot to move like an omni-drive?
I don't know how slick the flooring is because I was not able to attend a Kick-off.
But from what I have heard, it sounds pretty slippery.
Any guesses on how well this would work?
Edit: Hachiban beat me to it!