Early version of Cortana on Windows 10 leaked via video

Via rumors and other leaks, we've known for a while now that Microsoft's digital assistant, Cortana, should appear in Windows 10. Now, a video appears to prove it. WinBeta obtained the code to either Cortana or a leaked build with the Cortana executables built in, and gave Cortana a spin. Because the assistant isn't actually connected to the cloud services, Cortana throws up an error message when it's time for her to do anything truly useful. It's also early days as far as the UI is concerned: Cortana looks a little rough in this version, but she'll be spiffed up by the final release, we'd bet.