It's all about the nuance.

Facing significant pressure from Iraq's government, the US people, and from the international community, the Bush administration seems to be giving in to political reality.. kinda.

Are they going to agree to "deadlines for withdrawal"? No.

They're going to agree to a "time horizon" for troop cuts.

And what's the real, practical difference, you might ask?!

NUANCE!

By all means, let's have time horizons, gradual troop drawdowns, redeployments... but never a "deadline". 

Remember... If the Republicans leave Iraq, it's coming home victorious. 
If the Democrats leave Iraq, it's cutting and running!