Inception, which was by far my favorite movie of 2010, won best original screenplay, while The Social Network was named best adaptation.
I found the film compelling for its astounding visual effects as well as its startling originality. It most surely gave a whole new meaning to the word 'architecture,' as well as battering the viewer with mindbending new concepts. Fine acting from all the cast did not hurt, either. Personally, I would rate it as a ground-breaker on the level of 2001 and Blade Runner.
The other big contender, The King's Speech, was ineligible, being ruled out because union-recommended contractual methods were not followed. Or something like that. Legal union stuff that is beyond my ken. I doubt the makers are all that unhappy, though, the film already being nominated for 12 Oscars.
It will be interesting to see what film wins the Oscar for best original screenplay, as Inception is another nomination.