Copypaste from another thread, which explains pretty well why it'll never happen:
Buy a PC or don't complain about it, honestly.
When you buy a console you buy a gaming machine under the total control of a profit driven third party. Every game and every bit of DLC you will ever play on it is first screened and pre-approved by someone else, and sometimes free content ends up with a price sticker because the console maker says it should (Hi COD4 and Left 4 Dead ...).
Microsoft and Sony have no reason to allow user mods. Doing so would lengthen Skyrim's shelf life past what the official DLCs (which they get money from) do, and possibly make console gamers less willing to buy additional games / DLC for other games. Short shelf lifes for console games are highly desirable to Microsoft and Sony because it keeps the consumers riding the wave to the next blockbuster in each genre and their DLCs. See: Call of Duty, Battlefield, Brown Modern Shooter 342, etc. Quality user content would devalue official DLC for other games, angering other publishers and costing MS even more money than it would take to actually host mods. They'd also have to put resources into policing user mods if there was any serious functionality put into it, since we can't have Fox News talking about how Skyrim put boobies into the Xboxes of children everywhere and decrying video games as an extension of black magic (or whatever Fox has been up to since that Mass Effect piece).
Beyond that, it isn't possible anyway. The 360 and PS3 use hardware from 2005. They barely even run Skyrim at 30 FPS in 1280x720 (PS3 version came out doing less I remember ...) at nearly the absolute lowest settings you can run the PC version at. I was running PC games at 1600x1200 in 2002. Good mods are made to very high model and texture standards that would likely choke consoles, and most modded areas (Like Moonpath to Elsweyr) use a level of detail / foliage that can cause an FPS drop even on a good PC. Even if Skyrim on console did get mods the odds are almost all of the best mods would choke the console into low 10s / low 20s fps.
Modding on console is not feasible from a technical standpoint and would cost Microsoft/Sony money to support and police. Given that Microsoft has no qualms forcing 360 owners to pay for free DLC, forcing them to pay for almost entirely peer to peer multiplayer, and pushing mandatory console updates that put advertising on the dashboard, why would they spend considerable funds and effort on this? Given that Sony has no qualms pushing forced updates that remove features (Linux), threatening gaming news sites for publishing hardware / software rumors and giving PS3 exlusives low scores, and putting up high fees for publishing free content to "encourage" developers to release paid DLC, why would they? It's never going to happen. Then again, there is at least a chance with Sony given that they are desperate for any edge they can get these days.
Buying a console, especially a Microsoft one, and wanting mods or expecting to be treated nicely is like buying a tiger of questionable taming and wanting it to cuddle with you instead of eat your face. If you want user content and freedom you shouldn't be doing your gaming on a closed platform in the first place, and perhaps you'll think differently next gen. If you don't I guarantee mods of any serious quality will never see the Microsoft or Nintendo (they despise mods / emulators / anything community made on ideological grounds) sides. The only chance is Sony, and that's only if they're actually that desperate.