The USPTO claims that potential consumers could be unclear whether the video game called Killer Instinct was related to the crime drama by Fox, rather than the video game by Microsoft. Section 2(d) of the Trademark Act bars registration of a trademark that could cause likely confusion to the sources of the good or services of the applicant and registrant.
In September, word that Microsoft was attempting to register the trademark led to a lot of talk with our sources, who were saying that Microsoft was looking at bringing back an updated version of the fighter from the original Xbox. Microsoft has yet to confirm if they are working on a new Killer Instinct title, but if they are then chances are that it will be coming out under a new name.