Well, Inshallah.
The only bright side is widespread apprehension and fear in the Sunni Gulf Oil Shaikhs, and a feeling there that the US is shifting to a proShia strategy, spooking the Shaikhs, many of whom have sizable Shia minorities - Saudi, for instance, where the oil is located in the Shia provinces and those people have not shared in the wealth the Wahhabs have accumulated.
This outcome may not have been anticipated (that's a whole another thing), but it may be making the best of a situation.
Otherwise, Iran has certainly made out like a bandit with Saddam gone and a friendly regime there.
I agree Iran is the big winner in all of this. Saddam is gone and they share a border with a much weaker former enemy. They can wait us out all while funneling insurgents and bomb making material into Iraq. They've already begun forming alliances with Iraqi officials.