Greed will cause the big conferences to have their own basketball tournament. CBS or another station will always pay for the rights because it will still bring large ratings because of the size of teh schools and their fanbases. This doesn't even consider the fact that once the big conferences break away it will be impossible for schools not in those super conferences to ever steal a recruit away from a superconference school.
Rest assured, if superconferences happen, a separate basketball tourney will happen. It will only be a matter of time.
I do agree that the superconferences don't care about the other sports though - mainly because they don't make any money. Basketball makes a lot of money.