Yes, I do. I know there's mods like Issgard coming but they are a very long way off compared to how Bethesda could have released a DLC.
Okay, that is true. Have you played http://skyrim.nexusmods.com/mods/25704 by the way? I haven't myself, but Bethesda promoted it and people are saying that it is a good quest mod, so that could keep you busy a little bit.

As for outsourcing an expansion: I don't know if any "reliable" developer would accept a job to create an expansion for such a large game as Skyrim, and even larger universe. It is too low reward for having to study the lore and create a meaningful new expansion. So that would leave smaller developers who might not be as great, and could in turn make us wish they hadn't outsourced it.
But I'm not saying it wouldn't work, I just don't see it as anything that would happen.