We knew Cortana would show up on desktop sooner or later, even though it's never been announced, and now we have an idea of how it will work. Screenshots and video from WinBeta show what Microsoft's virtual assistant will be like when it finally and inevitably shows up in Windows 10.
Cortana already runs on Windows Phone, but this addition will let people ask the assistant questions from their desktops. WinBeta has access to a pre-release version of Cortana and is currently running it to see how it stacks up:
From the get go, Cortana can do pretty much everything the Windows Phone version can. This includes reminders, call people with skype, check my location/maps, play/pause music, launch apps, check the weather and more. Right now, Cortana doesn't have a personality in Windows 10, meaning she doesn't answer questions like "Who are you", however we have it on good authority that she will have this ability by the time she rolls out to the public.
Cortana will be the first virtual assistant of its kind to appear built into a desktop operating system by default, beating out Siri and Google Now on the non-phone side of things. Get ready to "OK computer" your butt off. [WinBeta via VentureBeat]