See, this is the thing that bugs me most about this whole audio bug. One of the main reasons I agreed to spend the ridiculous amount of money needed to get a MacPro was the hope that it wouldn't take 9 months to get driver fixes because it's all from one vendor. The reality is that (at least in my personal experience) Apple was *every bit* as unresponsive as what you'd encounter in the PC world. So why did I pay a premium for a MP and AppleCare?
FWIW, I've used PC's for professional work for well over a decade and never encountered a driver issue that took this long to fix. Just my own personal experience--ymmv. Don't get me wrong--I *love* my MP but after this experience I really don't know if I'll spend the money on Apple hardware again.
I would suggest your expectations are unreasonable. Here's why...
Mac Pro sales are probably 0.001% (or less) of the sales volume for iPhones. Thus critical mass for an issue takes much longer to achieve. Even the enormous sums of money we paid for these machines does not equip Apple with the resources to pursue every single complaint that is raised. An issue must achieve a certain level of critical mass before it warrants any kind of investment. In our case, this issue really didn't achieve sufficient critical mass until the blogsphere started reporting on it, and literally within a couple of weeks after that we had a fix. You should be very pleased with Apple's performance.
I'm not sure when you felt this issue achieve critical mass and warranted Apple's attention, but it certainly wouldn't have been in Oct. when one or two users first reported it. It actually took over 6 months before anyone noticed it... I got my Mac Pro in April 09 and didn't realize I had the problem until Dec. It wasn't really until Dec. that a critical mass of users on this forum got on-board, and even then (and to this day) there were several users who claim they don't have the issue which doesn't help build momentum. I mean, really, when did you honestly expect them to have issued a fix?