Rep. Paul Ryan (R-Wis.) has an easy-to-read explanation of the changes to the debt bill. The House Budget Committee website tells us:

In their new analysis of the Budget Control Act, the CBO estimates that the bill will reduce the deficit by $22 billion in FY 2012, and by $917 billion between 2012 and 2021. Under the bill, the President is given authority to increase the debt, under certain conditions, by up to $900 billion. Based on CBO estimates, the spending savings exceed the amount of this debt increase.

The revised bill will also include a point of order against consideration of a measure that would violate the discretionary spending caps put in place by the bill, which in the Senate would require a three-fifths vote in the Senate to waive. In addition, three provisions from the original bill are modified to address technical timing issues with respect to resolutions of disapproval.

The importance of the revision isn’t merely in the numbers. We've learned a lot about baselines in the last couple of days. As Yuval Levin explains, the up-front cuts assist future spending cutters:

This debt limit fight has set a precedent that from now on increases in the debt ceiling will need to be accompanied by equivalent cuts in spending, and those cuts will be measured by the CBO baseline, so cutting it by this much in the first two years will really shape the next round of the budget wars, which will come very soon. Front-loaded cuts have a kind of ratchet effect. And the larger cuts to the baseline in the following years (the revised bill’s cuts are larger every year than the original bill’s cuts) matter for the same reason—even if they don’t fully materialize (since one congress can’t bind another), they define the measure of future spending in every round of budget debates, which means that they make all future cuts larger in real terms.

It is, as many conservatives have said in floor speeches and statements of support for the Boehner bill, an important first step. The immediate cuts are small relative to our $14 trillion debt, but the trajectory of spending will now go down.

Before we get ahead of ourselves, it is important to remember this has to come to a vote in the House. (I suspect it won’t be all that close, unfortunately relieving some die-hards of the necessity of discarding their political purity.) It also has to get through the Senate, where other hardline Republicans, not to mention a whole lot of Democrats, will have to decide: Boehner or default?

And should this get through both houses, the president will have zero choice in the matter. He will sign it, and we will avoid default. And then the spinning begins. As for those GOP pols and pundits who favored the burn-down-the-building approach, there is perhaps time to reconsider whether they want to be on board with a vote that may change the course of our fiscal future and the shape of the Republican party.