In Pictures: 10 takeaways from Microsoft's Build c...
Something interesting that Microsoft worked into Cortana are reminders related to specific people. For instance, during his presentation, Joe Belfiore asked Cortana to remind him to ask his sister about her new puppy when he next spoke to her. Cortana noted the request and when Joe's sister conveniently called during the keynote, a notification popped up for him. The reminder would have also popped up had his sister emailed or sent him a text.
In Pictures: 10 takeaways from Microsoft's Build conference 2014