Blender is opensource and hasn't forked. So, opensourcing a project doesn't mean it will fork. Anyone who wants to can fork blender, yet nobody has done so. The Blender Foundation has no power to prevent forking and wasn't created to prevent forks. It was created to help further development. Such a foundation (or any of a number of other organisation forms) may work just as well for other projects, including projects for graphic card drivers.

And there's nothing to prevent a company from opensourcing drivers and yet managing their own source tree to create drivers that are under their control in order to be able to maintain the conditions necessary to be able to certify those drivers for hardware and/or OS'es.

Even though opensource means anyone may fork and may alter the code and produce patches does not mean that any such modifications must be accepted in every development tree. So imho forking is not something a company should worry about. And making source code available under an open source license does not mean giving away copyright. And it's always possible to license the code under multiple licenses too. IP is another issue, but that's a different discussion altogether :)

We are happy to work with anyone who is interested in this driver on getting the driver and graphic card up and running on their platform / reference design. This should be a relatively painless operation for any linux-based platform / reference design.

Cheers, I'd have no objections to testing it out once I order a card and get it.