The current official version of Tidalis is still 1.000. These later beta versions are previews of content-to-come, and will later be "officially" released via Steam, Impulse, etc, once our vetting process is over with the new changes and features.
Full release notes: http://arcengames.com/mediawiki/index.php?title=Tidalis_-_1.004_Beta_Release
is a pretty small release, simply dealing with a few bugfixes to the AI
in VS mode.