It's one of those beautifully vague phrases that's hard to interpret. Does he mean 2013, or a year from now, or literally the next coming year i.e. 2014, not 2013? Thing is, a 2013 release seems unlikely given work on the screenplay only began last month.
Then again, Ubisoft may be confident of an impending release on the back of its recent partnership with New Regency. The publisher said then the project is being fast-tracked, and Sardin's comment would back that up. Maybe we shouldn't be surprised if the next time we see Assassin's Creed on the big screen, it isn't (just) in the adverts.
Update: Ubisoft tells G4 an Assassin's Creed movie is in fact not coming in 2013. The official statement says Sardin was referring only to "further development on the film taking place next year." It goes on to shoot down any discussion of a possible timeframe.