Here's a good article from the Washington Post on the meeting held yesterday between diplomats from Iran and the U.S.:
A lot of byzantine diplomacy and politics at work here. We'll have to wait and see how this develops. But at the moment, Iran might come to the conclusion that it'd be best to cooperate with the U.S. and help stabilize Iraq; the sooner Iraq is stabilized, the sooner U.S. troops will start to withdraw and stop breathing down Iran's neck. But I'm probably being naive. Iran can afford to bide her time, especially if the U.S. backlash against a prolonged Iraqi occupation continues, which it no doubt will.