There's been a delicate dance all week between Speaker Boehner and Leader Reid over whose debt bill would get voted on first in their respective chambers. The dance was almost entirely driven by political factors. Basically, who would look best in the public eye and who would be in the strongest position to negotiate a final deal.
But with the House's failure to even take up the Boehner plan yesterday, that delicate dance is over because Reid is bumping up against Senate procedural deadlines. If he doesn't move today, he likely can't get his bill to a final vote before August 2, when Treasury runs of money.