Cortana will have a Larger Role in Halo 4
Throughout the Halo series we've seen everyone's favorite artificial intelligence (AI), Cortana supporting the story along with Master Chief. She's also provided players with tactical options, making her a great companion while in combat.
Cortana was created to adapt, a feature not shared by other AI, though the ability to learn, think, and reason comes with a cost. An AI gifted with these features typically has a lifespan of about seven years, and as Cortana has explained, can eventually "think herself to death". Can the emotional depth of such a non-human character indicate a new step in Cortana's presentation? After all, we could see a strong bond between Cortana and Master Chief especially towards the conclusion of Halo 3.
"I can tell you Cortana's going to be a focal point of Halo 4, for sure." Said Frank O'Connor, 343's franchise development director. I think a lot of people are speculating on Cortana's age and the effects of age on an AI, there's this thing called Rampancy which is really just any AI thinking itself to death and Cortana's been around for a while and most AIs have a lifespan of seven years. Cortana's a little bit different in that she's been exposed to a lot more technology and information than other AIs via the Forerunner lore and mythos. But her state of mind, her relationship with the Chief, they're all going to be core elements of the story and the 'human drama' as it were in Halo," O’Connor added.
Could we possibly assume that Cortana can take a "physical" form for the events of Halo 4? The fact that these types of AI live for a short time indicates more dramatic interaction between the lead characters. Who knows how much time has passed since Chief has been floating around in space? Halo 4 will be the start of a new trilogy, this time under the direction of 343 Industries. An ancient threat comes to wage terror on the universe and Master Chief and Cortana return to confront it.