The 1.0 version is available now. It's a windows installer, in the downloads area.
For the leading edge, version, you could try the svn /trunk.
There is available a beta version of FreeBlockSim in the downloads area.
Also, the SVN repository has the leading edge development status.
We are working hard to get the first alpha release on 12 March 2007. Please, take a visit round this date.