Microsoft demoed a lot of things at this years TechEd 2013, including the new fingerprint login system. The demo was presented by Chris Hallum, who talked about the new security features in Windows 8.1. The demo includes logging into the system with a swipe of the finger, adding multiple fingers to the login data, as well as creating Virtual SmartCards and gaining access to certain apps which use the finger scanning API.
Hallum says the fingerprint login system is fairly fast, and we have to agree. It's most definitely faster than typing a password or swiping on a picture. Windows 8.1 will detect the fingerprint and automatically select the user from the lockscreen too, which means you don't actually need to select your user before swiping on the device. Pretty cool.
The video featured in this post is a cut down version only demonstrating Windows 8.1. The keynote is a lot longer, and you can check it out for yourself in the source link below.