i pretty sure if you run Oblivion on top-quality you will run Skyrim on low quality
I imagine that unlike Oblivion, multi-threading will be handled properly, so multi-core processors will be used efficiently. I'm also hoping that CrossfireX/SLI will also be properly supported (although as I understand it, that's more of a driver issue than anything on the manufacturer's side of things).
Largely, running a 2.4 Ghz dual core has been very limiting for me to play either Morrowind or Oblivion (post-mods). I do plan to move to a Phenom II quad (or equivalent) pretty soon, and with more and more people on higher powered dual cores (even my girlfriend has a 2.8 Ghz dual), I imagine that everything will run fine.
Graphically? Well, if you think, Crysis 2 is supposed to be easier to run than Crysis 1, and
look better on max visuals, then I'm going to hope that TES V will run on minimum on similar hardware to Oblivion at its high end.
Having said that, we're guessing completely, and I'd love to hear a proper answer from the developers, but I doubt they know for sure just yet.