But the question is; how will they exactly play out and who shall be there? As we've seen in Morrowind, factions played a large part in you're "coming into power". But will it remain this way? I mean in Oblivion factions meant nothing but extra quests, which was a sad turn over.
And more importantly; who will be there in Skyrim? Besides the obvious rebellious nationalistic Nords and the fragile Imperial forces within the region there has to be some native factions as well as foreign. (Example; Morag Tong in Morrowind and Fighters guild, House Redoran, Imperial Cult, Tribunal Temple, etc) And usually it brought alot of story of the faction but it brought a good experience to it as well.
So what do you think which factions will be in there, and what factions do you want to be in Skyrim? I'd personally want something like a House Redoran-type faction within Skyrim, which is more than likely. Since the Nords usually are in hostile enviorments, there would be one faction (at least) to emphaize on strength and unity.