I mistakenly grabbed the latest WiX installer from here but the latest builds for version 3 are here under the weekly releases. There was an issue with the 3.0.2925 release with referencing the NETFRAMEWORK35 property in the WixNetFxExtension. This is fixed in later releases.

BTW, WiX rocks! Visual Studio 2008 integration is very nice. If you are looking for an alternative to the stock VS setup project and need more control over the MSI, I'd check it out.

I love WiX, but I hate that you have to specify the id's and short filenames! This really slows you down when you have a lot of files to add. I have read that these may be optional in v3 and auto generated by the compiler. Until then you could use this Visual Studio addin that that allows you to randomly generate and insert id's and short filenames as well as insert some common tags with the aformentioned attributes randomly filled in. n-joy!

Visual Studio 2005

Installer: WiXHelperAddin.EXE (217.21 KB)
Source: WiXHelperSource.zip (258.91 KB)

Visual Studio 2008

Installer: WiXHelperAddin2008.EXE (217 KB)
Source: WiXHelperSource2008.zip (63.89 KB)

PS: Also, check out the GUID inserter (Which also appears in the image below...); this is very helpful for WiX development!