As has been expected, Microsoft's virtual personal assistant, Cortana, is an integral part of Windows 10. According to Joe Belfiore, corporate VP of the Operating Systems Group in Microsoft, Cortana is able to learn about users over time, bringing together everything she knows about them to deliver reminders and suggestions in the Calendar, taskbar and new Spartan browser.
As she's constantly connected to, and trawling the internet, she can deliver additional information on web pages. Belfiore gave the example of a restaurant, where Cortana automatically delivered information on the venue's menu, opening hours, and directions from his location. How useful (or annoying) this will be remains to be seen - we weren't the only ones to feel shades of Clippy in the sassy AI's attitude and functionality.