I'd guess its some hexagonal shaped object that only uses half the casters to keep the cost down since they are $22 each, not exactly cheap. But 5 inch casters? Maybe we finally have a 'hilly' field to play on, now that would be interesting.
The puck was in the 99' game, it was on casters and had poles sticking up on each corner. You got points for climbing onto the puck at the end of the match or for hanging from a pole. Then the puck also gave points to an alliance depending on what half of the field it was in.