We've just done a quick bump up to 4.0.1 to add some beta Windows Vista support.
The wiki will be updated soon to add some windows specific instructions to the install procedures.
The automated installer may not work properly yet for windows, but we'll bring it up to speed as soon as possible.
Visit the Omnium Open home page for more info.
P.S. another point to note is that we have halved the size of the source tarball, thanks to the removal of some unnecessary font files.