Well, I'm a week away from launching a private beta of a FileMaker-driven database solution I've spent the last 18 months building (it has a full user interface - which is why it took so long).
Hopefully followed by limited public beta in August and full release in January.
Good luck with that! I've not used FileMaker before -- my impression is that it's the Mac equivalent of Access. Is it substantially different from an SQL-speaking RDBMS? If not, you can scale up by allowing the back-end be a PostgreSQL or MySQL database