We aren't ATI's market.

Erich Schubert noted that ATI is holding onto their closed drivers. While it's unfortunate, I don't think this should be surprising to anyone. NVIDIA and ATI make their money by selling cards for gamer types, who make an art out of trying to get the latest super hardware to play the newest snazzy games on. They don't give a hoot about source code access -- after all, they're probably running proprietary games on a proprietary operating system anyway.

Free software enthusiasts, on the other hand, spend their free time hacking code and so don't have time to play the massive productions the game industry puts out nowadays; frozen-bubble or Wesnoth are about as much gaming as we have time for. As a result, we can do just fine with a video card capable of displaying Emacs, a couple xterms, and maybe a graphical Web browser -- and the built-in graphics card (usually Intel) on the motherboard is just fine for that. We also tend not to run Windows or OSX, where 99% or so of graphically intensive games come out, so even if we HAD free time for gaming we wouldn't be able to do it on a free system.

As a result, while I'd certainly like to have free ATI drivers, I think it's unrealistic to expect them anytime soon. ATI is a company, not a charity, and they will not provide source code or specs until it will clearly benefit them more than it hurts. If you don't believe me, try walking into your manager's office and saying "hey, I have a great idea! Let's give away all our secrets without any clear way to make money off it!" and see how he reacts. (note that this experiment may not apply to the 1-5% [0] of readers lucky enough to work in academia)

[0] this statistic determined by the HIGHLY SCIENTIFIC method of picking a small number at random.