The former opensimpad distribution is discontinued and only availabe for historical reasons.
Well, at the moment this is only a concept. It's complete when it will be complete. It could be also another Vapoware so don't bag me if there will never be a release.
But SlackPAD Linux has now a sourceforge.net account. There you will find a thubscript userspace keyboard driver and the latest 2.6 SIMpad Kernel development status.