Laurent Kempe has created a sample of the on10.net login modal screen using Atlas controls.  I actually haven't tried it but it looks similiar in the screenshot.

Its interesting to me because currently in the 10 codebase we are using custom controls where we define every bit of html and JavaScript.  Since the launch of 10, a new version of Atlas has been released and we're looking towards leveraging the existing controls available.  I'm really looking forward to digging deeper into Atlas controls, behaviors along with CSS adapters.  I think that may save us a bit of time in the future writing custom controls.