This is an interesting article on a helper assembly for Wix called Wix#. I've never been a big fan of Wix, mostly because it changes so rapidly. But this program provides some excellent help for developing an installation program. Wix# is not a GUI. I hope this program receives further development and will be maintained by the OS community. It definitely has promise.

Wix# (WixSharp) - managed interface for WiX.