How should digital preservation tools be funded?

This is a bit of a broad question, but I can still venture to give my perspective on what I think are two related and rather strong models for doing this with open source software projects. 

• Open Source but Membership Fees for Participation in Governance: I think this is emerging as one of the best ways for thigns to work. ArchivesSpace has a membership model like this and this is the kind of thign that BitCurator is exploring this kind of thing and DuraSpace has had this kind of membership model for a good bit of time. What is nice about this approach is that the underlying software is avaliable to everyone to explore/tinker with but orgs that are commited to using the tools and systems pony up to provide the kind of sustaining funding that will cover core maintaince and work on the projects that can't just come from project based grant funding.
• Freemiums and RedHat style pay for services: Software projects like Zotero and Omeka have found their way to some mode of sustainability by in the formers case selling storage space and in the latter's case selling a hosted version of the software. In these cases, instead of participating in governance, organizations can pay for the convienence of paying for extra utility and simultaniously supporting the open source use of the software in general. I would put Artifictual's buisness models in this bucket too. Anyone can use Archivematica, but orgs can pay Artifictual to do focused development on new features as well as various other services.