WinRT/XAML is a different technology than WPF and none of its WinRT UI will work with WPF. Additionally these transitions seem to be using some different mechanism than regular Storyboards, so there is likely no way to just extract them to something that would work with WPF.
Your only option would be to implement something yourself and make it look good. Or alternatively give up support for Windows 7 and implement your application as a WinRT app for Windows 8.
