In short, we can't get there (the moon) from here. The "program of record," (i.e., Ares I&V, Orion & Altair,) can't be accomplished on the existing budget.
Of course there will be a political dimension to all of the fingerpointing that results from this conclusion. Critics on the left will blame Bush for not giving his vision an adequate budget. Critics on the right will accuse Obama of "throwing in the towel" in some non-existent moon race with China when he likely tells NASA they'll have to survive on their existing budget.
Plenty of fingers will point towards Mike Griffin and the people who worked directly for him, for pitching an unsustainable architecture. There's no doubt that ESAS was needlessly expensive, and plenty of cheaper alternatives existed. But Griffin's critics can't say with any certainty if their alternatives could have been fit within the existing budget. ESAS was colossally unaffordable, while something like DIRECT or EELV might have been marginally unaffordable. In the end, we're still not going to the moon anytime soon.
The one area where there's no excuse for either Mike Griffin or Sean O'Keefe is the gap between shuttle and Orion. The historical example of Apollo should have convinced both NASA administrators that capsule development would be a seven-year effort. If a contract for Orion were awarded in late 2004 (a reasonable amount of time after President Bush's January 2004 speech setting a goal of 2011-2014 for Orion,) we might have a manned capsule by 2011. Even with the Orion contract being awarded in 2006, first manned flight by 2013 would have still been realistic--if the capsule's requirements weren't continually shifting with each setback in the development of the Ares launcher. If the capsule people had a stable set of requirements they were working towards (i.e., the established performance of the Delta IV Heavy,) we wouldn't be seeing the gross schedule slips we've seen in Orion's Initial Operational Capability date up to this point.
Every time I talk to my friends within the aerospace industry, I hear the same set of doubts about why we're "wasting money" by paying NASA to launch humans into space. There's a growing sense among the public that there are diminishing benefits on earth for all the money the taxpayers spend on space activities. I'm certain that many people who used to support NASA are growing increasingly dismayed by the "competency gap." The agency has lost the ability to duplicate so many of its past triumphs.
Maybe the solution to all of NASA's ills is to hurl more money at its problems. But if the agency can't demonstrate why it can be trusted as a good steward of taxpayer funds, and why it's still relevant in the face of private-sector space programs, does it deserve the extra bucks?