From the WSJ:
Agreement Reached on Bailout Ahead of High-Level Meeting ... lawmakers agreed to legislative principles that would approve Treasury's request for the funds, but would break it into installments ... Treasury would have access to $250 billion immediately, with another $100 billion to follow if needed. Congress would be able to block the last installment through a vote if it was unhappy with the program.
This was one of the good suggestions that came from Congress (and probably all of you).