With the need for organization being so important in order to move forward, what can be done to bring about some kind of unity in the Syrian opposition movement? With multiple competing factions, what actions can the Syrians take and what can the international community do to encourage some degree of unification?
1. Elections: Logistically, this would be impossible. Carrying out any kind of vote for an opposition leader is unthinkable when shells are falling and snipers are perched on rooftops. Remember, organizing an election requires a level of organization in and of itself.
2. Exile community leader: The next Syrian Mohamed El Baradai is not likely to pop up, and if he did (it would most certainly be a "he"), the chances of him having any degree of legitimacy within the Syrian opposition are minute-- just like Mohamed El Baradai.
3. Designated partner: The international community -- most likely the UN -- could choose a representative who they feel would make the best leader of the Syrian opposition and the best negotiating partner. This could go two ways: Syrians rally round the Chosen, or Syrians shun the Chosen. The latter is more likely, especially given that there are no front runners for the title. Anybody chosen today would be plucked from somewhat obscurity and be interpreted as a Western stooge. It is possible that should certain leaders begin to make more of a name for themselves, a possible partner could be "preferred" by the UN. Until that time, choosing a person would condemn them to irrelevance.
4. Covert aid: A trickier option than Option 3, covertly aiding one leader is a viable alternative. In this scenario, some party (probably unilaterally) sends aid exclusively to one leader in Syria with the hope that that leader's subsequent rise would be viewed as an exclusively Syrian affair. The outside interference would never be seen. To the unknowing, a Syrian leader legitimately gained power in Syria through Syrian actions.
A problem with this approach is that international organizations rarely if ever agree to mutually support covert activities. It sort of runs counter to everything that is sacred to multilateralism. The exception would be a US/UK joint operation, or a US/Pakistan operation. But I don't think we'll ever see a UN sponsored covert aid program. That's not to say that the "Friends of Syria" couldn't turn a blind eye to some back room dealing, however, I don't think it is likely.
5. Civil war: The least desirable option, but also one of the more likely. In this scenario, there is no outside intervention. Instead, different Syrian groups will fight Assad and each other in a battle of attrition until one group emerges "victorious". With the strength of the Assad military, one can imagine an Afghanistan circa 1979-style situation, where the priority amongst the mujahideen was to fight the Soviets first, and only once the Soviets were gone, fight each other. Any backing by the international community for one of the factions will help with the downfall of the regime in the short term, but in the long term, that faction now has an advantage in the subsequent civil war -- which is probably a consequence that was never considered by its international benefactors.
6. Combination: These options are not mutually exclusive. One can imagine Option 5, with one faction publicly preferred (Option 3) and covertly supported (option 4), leading to a national election (Option 1).
My gut tells me the preferred sequence in Washington is Option 4-> the downfall of Assad ->Option 1, without any witnesses or fingerprints.