Well, if BGS get this right, it'll go a long way towards a great game.
I'm hopeful that we get:
1. Interesting and substantial interplay between Dunmer and Nords. And I hope it's not all just "Me Nord hate Dunmer invading Skyrim". I can imagine that there are some Nords who would be more understanding of the need to accommodate Dunmer refugees, given that Vvardenfell exploded and the Argonians have invaded. Indeed, this could provide further political complexity just among the Nords: those who just want to get rid of the Dunmer, and those who want to provide some sort of haven for the Dunmer.
2. The Nordic clans are not just divided into pro- and anti-Empire. I'd like to see some nuance, like we had in Morrowind. Perhaps one clan is pro-Empire, but this is something more like advocating an empire of Men to rule over Tamriel, and they see this Empire as having its true seat of power in Skyrim, rather than Cyrodiil. Perhaps another clan is pro-Empire, but that is because of the trade and security benefits that it brings; other things, like aspects of Imperial culture, the clan opposes. Perhaps another clan is anti-Empire, but they are fairly non-violent in their opposition; they mostly adopt a policy of isolation, only fighting back against the Empire when they see the Empire as encroaching upon their territory. And so on....
3. Finally, I'd like to see the Guilds tie in to this political context. The overarching narratives behind the Fighters Guild, Thieves Guild, Mages Guild (or whatever their equivalents will be) should be grounded in the social and political context of Skyrim. Perhaps one of the Guildmasters in the Fighters Guild is vigorously opposed to resettling the Dunmer, and so a lot of his quests require you to extort Dunmer in refugee camps; another Guildmaster, however, is opposed to this, and his quests will be more about helping the Dunmer fight for themselves against xenophobic Nords.
All just for example, of course.