According to Nasa Watch (click if you like, or not): http://www.nasawatch.com/
If MSL doesn't go until 2013, there's a chance MRO won't be around anymore, so we may well need another orbiter anyway.
Given the stunning success of MER both from engineering and science perspectives, and how the Meridiani findings keep hope alive for the aerobiology crowd, this suggests nothing is off the table. It could be a a somewhat reasonable decision that MSL just won't be technically ready by 2009, whether we're willing to fund it or not, but I get the snse funding is a big factor. I won't expect to see many planetary new starts for a while....
At least Griffith has been clear about this: the President has told him to ensure create a new national manned space capability (priority 1, as far as I can tell), and to get on track to land men on the Moon again. Everything else can be sacrificed if need be. More honest than the Goldin years, but not exactly the priorities I'd choose.
Space/Science » in reply to Mars Telecommunications Orbiter Cancelled
And Mars Science Rover delayed to 2013, possibly