Pelosi says that the Democrats won't cut existing funding for the war in Iraq, but they will make it difficult to pass funding for the increase in soldiers. So, they just want to stay the course.
Mind you, Bush is not a micromanager. Bush, as he did when he was governor of Texas, hires the best people he can and delegates almost all his authority to them. It is obvious that the actual nuts and bolts of this new plan came from Gates and the new generals who specialize in counter-insurgency. The Democrats have shown no such source of qualified sources for their lack of a stance let alone a better plan.