I certainly hope nothing huge. They will be getting pennies back on the dollar for anything they put into that place. I'd rather just see them put that money in a separate account, let it grow interest, and use it 10-15 years from now towards a new arena.
Edit: I'd be all for buying those lights and stuff that they had rented for the Kent game. It helped create an exciting atmosphere and is something they can take to a new arena.