According to the article at KDrama Stars, it seems that Michael Fassbender has distanced himself from the production of Assassin's Creed, which has a twice moved release date of August 2015. I'm of the belief that this may be ringing true, and if so, it's unfortunate, but it all comes down to business. Look at it this way - for a film that will be heavily relied upon CGI and fight scenes for which Michael has to train for, if they plan to release this in just 14 months, this film should be filming RIGHT NOW, really since like March. But it ain't. We all know how busy and in-demand Michael has become and I'm sure many other fantastic scripts have been brought to his attention, namely the follow ups for Prometheus 2 and X-Men: Apocalypse. And that's not even mentioning the one or two yet to be announced Indies this man will surely sign up for. He's currently preparing to film Trespass Against Us which will be filmed in Ireland and England this summer.
So chances look slim to none that Michael is indeed still attached to Assassin's Creed because the time frame conflicts with too many other projects that he is contractually obligated to. I'm perfectly fine with this decision as it did seem too good to be true when it was first announced. Video games turned into movies are a tricky investment. Although I'm not a gamer, I do like some of these games to movie projects, but when some fail, they fail awfully and I don't want something that will end up straight to DVD for Michael, he's above that as an Oscar nominated actor.