In reality, I don't think this is a biggie. I suspect a good many of us have that entire firmware folder backed up, so all we'd need is a sticky, where anyone who needs firmware posts a wanted notice and we can email it out. Unless we're into copyright problems?
As has been mentioned, it's years since we had any firmware updates, and if new feature firmware becomes available, I personally don't think it's unreasonable for M to charge and distribute it via dealers (for 'in person', or other onward distribution)
Cheers
George