There is still a big difference.
With documentation here and source code open, I pretty much have guarantee that the hardware I have now will still work in years to come. Even if the driver would be abandoned by AMD and not be further developed, chances would be very high that it would at least be adapted to new kernel versions and similar changes.
Example: I'm a victim of the Intel GMA500 mess. There doesn't seem to be a chance I will ever be to run my laptop on a newer kernel or any future Ubuntu. I will probably never be able to use it like it is supposed to because the occasionaly wake-up crashes will never be fixed. I am sure these problems would already be fixed if the sources would be open source, regardless how abandoned the code is by the original programmers.
Still, I understand you.
I am really really sad that the community does very little except testing. Open specification was supposed to help the community, it was lobbied for by the open source people for so long, and now it seems that the open specification did not help much. Would the open source radeon drivers have been programmed based on closed documentation, how much behind its current status would it be? Not too much I feel.
I am especially sad because this gives other manufacturers good reasons to keep their specifications closed, because opening them clearly doesn't necessarily result in any advantage.
Note: This is not a complaint to anybody.
I read a little in the specifications, and there's no way I would ever start working on the driver unless I get one or two years of education in hardware/software co-design and a full time job. It's just too complex to work on one or two hours after work.
I don't complain at Ubuntu or Redhat that they don't invest in the AMD driver, because their job is to make the software easy to install and the hardware to work. They have the closed source drivers, and until AMD starts to abandon current hardware in their closed source driver I don't see a need of Ubuntu to invest tons of money in drivers of one of the graphics card manufacturers.
Really, I can't see any company but AMD who has enough motivation to spend a lot of money (just some money wouldn't be enough) for these drivers.
This leaves me grateful for AMD that pay as much as they do and be thankful for the work their open source developers do and be frustrated as hell that the biggest strength of open specifications and open source failed in the development of modern graphics drivers.