I just finished decorate my Ubuntu Precise Pangolin with OSX Mountain Lion theme. I use Gnome Classic, Docky, Macbuntu icons and Wildcat 1.5 Beta theme.
Unlike Mountain Lion, the window's bottom corners are not rounding in Precise Pangolin. So I need to adjust a bit the buttons and window corners using Emerald. I use Wave Lion 1.0 Emerald theme to set the buttons in right position and right shape.
There are few more works still in progress, but it's already confused me whether I work in OSX or Ubuntu.