Fox and Microsoft have come to terms over Killer Instinct trademark
From Neogaf:



The Applicant has entered into a Coexistence Agreement with the Owner of the cited application, a copy of which is submitted herewith. As shown in the attached Coexistence Agreement, the Owner of the cited application consents to registration of the subject application.
http://tsdr.uspto.gov/documentviewer?caseId=sn85727092&docId=ROA20130402183309#docIndex=1&page=1
http://www.neogaf.com/forum/showthread.php?t=534603








