Hadn't heard about this anywhere else, but the Windows Whistler beta apparently offers a feature called Remote Assistance. It seems similar to Network Assistant on the Mac, the same reason I put VNC on my dad's computer:
Here's how Remote Assistance works: You email an attachment that, when clicked by another Whistler user, lets the recipient log on to your system in a prescheduled help session. The recipient can control the mouse cursor on the remote system, and the two of you can chat over an instant messenger. To avoid any potential security threat, Whistler offers a password-protection feature to log you into your help session, and you can turn away your helper or close the session if you feel uncomfortable.
I can see why they're not publicizing it yet, seems like a security nightmare waiting to happen once the uneducated masses find out about it.