Update: Despite Spencer's assertion that Titanfall is "exclusive," a new post on Xbox Wire shows the game is also coming to Xbox 360 and PC in addition to Xbox One.
Original post: During the Microsoft's Xbox One event at E3, it was revealed that Titanfall is an Xbox One exclusive by Microsoft Studios head Phil Spencer. The shooter comes from Respawn Entertainment, the outfit from former Infinity Ward head honchos Vince Zampanella and Jason West. Back in March, co-founder Jason West left the company.
Titanfall's brief trailer showed a heavy emphasis on war (surprise!) in a futuristic setting with mechs and jetpacks. CEO of Respawn Entertainment, Vince Zampella, took to the stage following the trailer and revealed the Respawn's partnership with Microsoft prior to some multiplayer footage of a capture-type mode. Titanfall will launch in the spring of 2014.