Good idea. I'm sure there are enough companies out there with data "stuck" in domino without the technical resources on hand to make it accessible that you would probably sell more than a few licenses. It can't hurt to publicize it and make it as "turn-key" as possible. And just because you sell a product doesn't mean you can't keep doing what you do, so I don't see a down side to marketing your tool. Put it out there and don't worry overly much if it succeeds right off. Getting market share is a long, hard slog requiring persistence and a perpetual positive attitude.
A suggested feature might be making it target system agnostic. You could do this with MSADO as your data layer with simple connection string changes between MSSQL, DB2 and ORACLE.