Oh, I just had a thought. If the sillybuster DOES happen, the Republicans can't/shouldn't pull the trigger on the constitutional option today, because they will need Ensign's vote on the question of using the fillibutster on judicial nominees. If there are only 99 senators available to vote, Cheney wouldn't be needed to 'break a tie'. The Republicans may have to wait until tomorrow to put the rule to the chair, assuming Ensign will be there by then.
My guess would be Frist will hold another cloture vote when Ensign is back first.
The constitutional option will be under active consideration at the time of the SOTU address. Wouldn't that be interesting?