There are a couple key issues with Syria, for one the opposition is very small and there is a good chance that the indiscriminate killing will continue on for a very long time. Very different from the Libya situation.
Second, in typical middle eastern political fashion you have an incredibly convoluted history of support. Assad has historically (via Iran) supported Hezbollah in Lebanon who is clearly very shiite, if not for the arms he provides Assad would likely be just the type of leader they rail against. That being said, there are now concerns that the Syrian movement is being taken over by Sunni militants who see this as the new battleground to fight Shiites, essentially taking a reformist movement hostage with a fundamentalist approach. And that never goes well.
All that being said you have the international community essentially appalled by the level of violence, yet scared S-less of the ramifications if the opposition is supported. Do we send weapons to folks that are keen on turning Syria into a terrorist state (perhaps more so that it presently is)?
So that is my take. Who knows that the right course of action is. It sucks that a legit movement is being compromised and innocents are suffering. The middle east is an incredible place, it also has WAY too much baggage and old grudges, sprinkle in the nuts and you have a recipe for disaster.