What if they held a filibuster, and nobody stopped voting?

[JoeTheJuggler]

I'm guessing they decided not to go through with it because it would be extremely awkward for Dick Cheney, as President of the Senate, to personally take charge of the Senate on behalf of the Bush Administration... which is the same reason Obama hasn't bothered dispatching Biden to try the exact same thing now.

Maybe. But I think the main reason the Senate has not gone with the "nuclear option" is that the present majority realizes there will be times when it is the minority, and may want to avoid a vote by using the filibuster.