There's no real way to have consoles be able to download player-made mods, and it would be ridiculous for Bethesda to pick Oblivion mods that players made and put them into Skyrim where everything is going to be completely different. If you want mods, get Skyrim on the PC. It's worth getting a gaming PC if you don't have one just for the hours and hours of extra gameplay added by Morrowind and Oblivion mods, as well as the millions of Skyrim mods that will come out. Not to mention fun for yourself if you fancy the idea of making your own mods and want to mess around in the Construction Sets.
First it's no way skyrim for pc can run Oblivion mods, you could not use Oblvion mod's in fallout 3, or Morrowind mods in Oblivion.
Yes lots of mods was ported from Morrowind to Oblivion.
This usually require serious rewriting.
Bethesda also follow the mod community and might include functions from mods.
One simple function I hope is included is that harvested plants look harvested, Point lookout had this for the fruit you harvested so it's hope.