This week's Aviation Week has a short piece in "Washington Outlook" about the tightness of the MSL schedule to hit the 2009 launch window. The piece says "NASA managers say there is still time to make the 2009 launch window for the MSL mission -- if enough extra money can be found. But sources... worry there's only about a week of wiggle room to get the critical launch/cruise environmental tests underway..." "...the next president will be able to take a broader look at the mission when it comes up for review again in January." Alan Stern is quoted as saying that he would ask two questions: (1) how much will this hurt other parts of the Mars and science programs, and (2) is there really time to complete the testing to provide high confidence that the mission will succeed?
I obviously have no insight into the internal state of affairs. As an outsider with experience in multi-hundred million dollar development efforts, however, the '09 launch is looking like a hail Mary pass. Everything necessary to meet the '09 launch has to be done, so there's no downside to trying to meet the current schedule and $3-400M upside in additional costs not incurred with a slip to '11. I would not, however, be at all surprised to learn that the mission does in fact have to slip. Either way, the additional costs are sufficient that there will be implications for the rest of the science program for the next several years.
I don't think the next president's staff will get involved in this issue in any serious way. Whichever team it is will have their hands full with lots of other issues. There will be a budget submitted in Jaunary for the entire government (most of the gov't is currently on a continuing resolution at '08 levels until the next president submits his budget). MSL, however, is very small potatoes. I think NASA will be told to deal with it on their own within whatever budget is approved.