I have to agree with Rumsfeld on one point, there shouldn't be a "timetable" put in place with regards to a withdrawl of US troops from Iraq.
What they should have to do however is come up with some concrete targets that have to be met that would allow US troops to be withdrawn (set the numbers of Iraqi security forces that need to be trained, etc.), set up concrete plans to meet those targets, and have serious oversite of how things are going with regards to meeting those targets.
To me, setting a date is meaningless. What needs to happen is that the new government in Iraq needs a security force that can keep the new government in power and maintain order in the country after US troops leave.
If there is a date set, the security forces in Iraq aren't capable of maintaining order, and the US pulls out anyway, then you very likely could see Iraq turn into a bigger breading ground for terrorists than Afghanistan was prior to 9/11.
That would not make things safer for US citizens in the long run and would waste all the sacrifices that have been made by our troops up until this point and in the future.
Congress should be pushing for a plan. But, they shouldn't be pushing for a date.