Just a short post here to point out some of Fredrik Grohn's latest handiwork. If you look on the right of the WiX toolset website, you'll see a new link called Manual (WiX 2.0). That's an online version of the content in the WiX.chm. Eventually, a Manual (WiX 3.0) will show up.
Now that the build process is generating the web site for each weekly build, you'll see more content showing up on the web site now.