President Bush meets today with the majority and minority leaders of the House and Senate to discuss war funding. With Bush threatening to veto any measure that includes troop withdrawal deadlines, and the current House and Senate bills containing such deadlines (albeit somewhat different sorts), negotiation theory says that the outcome should be some sort of a compromise. Neither side can afford to simply walk away, because Bush does need the funding to continue the war (although he can probably get by for a few months by shifting budget items a bit).
We would expect that the exact nature of the compromise should depend on the relative bargaining strength of the parties, but that's hard to gauge for at least two related reasons. First, although Democrats have public opinion on their side in wanting to set a timetable for troop withdrawal, Bush can portray the Democratic position as failing to support the troops in the field (even if that's not the Democratic intent). It's hard to know in advance which view will prevail with the public. Second, so as to avoid the perception that Democrats don't support the troops, the Democratic leadership has stated unequivocally that it will fund the troops, full stop. That suggests that if Bush vetoes a version of the bill with a timetable for withdrawal, Congress (probably meaning nearly all Republicans and some Democrats) will then pass a simple funding provision. So much for the power of the purse.