Probable.

Possible, but China and Russia's stance can hardly be a surprise, and represents a problem for a particular strategy, not the overall goal.  I see it as a lull before the storm.  Iran is still a major problem for the US imperialists, as they are a serious threat to US hegemony in the gulf region.  That hasn't changed, and I don't see any development of a different strategy from the Neocons.  If anything has changed, it's just that reality has intruded a little in regard to the difficulty of such an operation, and they need a little time to get the pretext just right (for consumption in the US only).  They'd rather go in under cover of the UNSC, but if need be it can be used to prove that the UNSC is useless, and the sheriff had to ride in alone.

Soon the time will have run out on the latest offer made to the Iranians, and the Iranians will continue to try to drag it out without outright rejecting it.  I doubt they have any intention of giving up the nuclear fuel cycle.   So what will we do then - just say "ok, then, never mind"?  Not likely, and the rhetoric is increasing already.

This is a regular strategy of these people, both domestically and otherwise - you use a tool like the UNSC to enable you to do what you want with some level of legitimacy, and if you cannot you do what you want anyway, and thereby destroy the credibility of the organization that opposed you.  You count on the fact that no one will actually try to enforce the rules.  In the end you have absorbed new powers.

BTW, I find it very interesting that the saber rattling over N Korea is so muted by the administration.  It was the liberals who wanted a preemptive strike, while Cheney played it down.  Why?  Because they have nothing we want, and we must save the military force for those places resources we actually care about.  

With oil at $75/barrel, there is a 0.01% chance of any sort of military action on Iran. I think the only thing that may come out of this are more sanctions, which is laughable because Iran has been under a harsh U.S. trade embargo for 27 yrs. Oil has been used as weapon in the past. Now, it is a very effective shield.