From what little I've played with it, you need to install xcompmgr (which I used to get the shadows) and transset to get transparencies to work.
I can't recall the exact website, it was after finding an obscure link via google/linux.
I didn't play with it very long though, as it's still buggy as hell. If you have an NVidia card there is an option to use it to accelerate the 2D display. Otherwise the shadows make everything extremely slow. About the best I could use it for was to look at it and say 'ooooooh'
It shouldn't be long before xcompmgr and transset are incorporated into various desktop managers (after more debugging).