Microsoft now owns Nokia. So they'll need to hop on the bandwagon and get themselves a mobile personal assistant. Like a Siri. The feature will tie together all of Microsoft's products and it will be named Cortana after the artificially intelligent character in Halo.

There have been clues of her existence for a couple of months already. She most recently appeared in an all called "zCortana" found in a leaked early version of the Windows Phone Operation System.

Even Bing director Stefan Weitz alluded that Microsoft was building a Siri and Google competitor.

"We are not shipping until we have something more revolutionary than evolutionary," he told CNET in July. "There are teams working hot and heavy on this right now."

Even Microsoft CEO Steve Ballmer also alluded to "a family of devices powered by a service-enabled shell." Ballmer wrote in the July strategy memo:
Our UI will be deeply personalized, based on the advanced, almost magical, intelligence in our cloud that learns more and more over time about people and the world. Our shell will natively support all of our essential services, and will be great at responding seamlessly to what people ask for, and even anticipating what they need before they ask for it.
ZDNet first reported details about Cortana and The Verge followed up with screenshots. Check out the video below: