This is an implementation to style useraccounts with Material Design Lite (MDL) based on the unstyled.
Main concept is to apply MDL grid, cell and shadow classes to the templates appropriately.
WORK IN PROGRESS - Only main sign in and sign up screens tested. However, the at_ templates seem easy enough to customize. So maybe you can help to fill in the blanks for any at_ templates.
Adding this package with meteor add useraccounts:mdl does not install CSS from MDL. You will need to make sure MDL is properly initialized. This can either be done by manually adding MDL support to your project or using some of the MDL packages from Atmosphere.
The zodiase:mdl package seems to be pretty well maintained. I was using this during development.
Anyone is welcome to contribute. Submit issues. Fork, make your changes, and then submit a pull request.