Although both the US and Iran are currently denying direct co-operation with each other, it's an intriguing thought to wonder who is talking to who behind the scenes in the latest coalition. Liaison officers??
On a separate note, I understand that IS/ISIS/ISIL has now been formally rebranded (at least in military circles) as Da'eash (pronounced Daish). It is allegedely a derogatory Arabic term for 'poncey terrorist scumbags' or words to that effect....
I presume that the Americans must also have been talking to the Syrians before launching airstrikes there as well unless their defences have degraded significantly during the civil war or the US are restricting their attacks to targets well away from government forces.
BTW Da'eash is in common use in Iran to describe IS.