To me, what will be really interesting is what kind of defense Russia puts up for Syria against any sort of cruise missile and aerial assault. Russia has been claiming to have some very effective SAM and EW capability in place.
If there was an assault against Syria and suppose Russia effectively blunted it, there could be a significant shift in how the world views Russia vis-a-vis the West, and especially the US. On the other hand, if the strike was effective, Putin's claims about his new weapons systems (and thus his reputation) would take a hit.
Of course, the possibility of some sort of escalation between the West and Russia is also worrisome.