Well presuming that i still had source code available to me then I suppose i wouldn't laugh you out of the room. But I suspect I would still insist that anything that encapsulated my business processes would remain my posession alone.

Update: Just to make a point I dont have a problem with the use of open source and the process of contributing back modifications made to it. Nor would i have a problem with opensourcing much of the generic part of a product developed for me. I do mind having that code be closed source and not available to me as the customer who funded its initial development.