It's not about the temp! He is lucky enough to have a dual processor machine so although it heats up, not to the same extent as a quad core machine. He is however still sucking way more energy out of the wall and losing substantial performance by playing audio. If you bought a brand new car, and whenever you turned the stereo on, it consumed 25% more fuel, ran hotter, and went slower, would you not be annoyed?
I know it is annoying, and I'll try to get it fixed, but I just said that it is not something to be overly worried about.
Speaking about the car, in your example, if it is the car I use to do my job, I'll use it with the stereo switched off, while waiting for the manufacturer to fix the problem. I'm not denying the issue (we have something like 12 Mac Pro's, different models), I just said that in his specific case (49 degrees C cpu' s temperature) it is not an issue to be overly worried about.
The loss of performance seems to be the real problem here.
Cheers