We don't plan to fork qemu, too much good stuff is being added there. However I want to submit the patch for inclusion only after (if?) the driver is merged into the mainline kernel. The patch is also not very pretty at the moment.
I would recommend the opposite approach. Something can go in QEMU more quickly than in the kernel and you'll get people actually testing it. If it gets in the kernel and there's no major userspace presence you won't have nearly the same amount of testers...