On the basis of pre-release information, the new MacPro doesn’t seem to be ideally targeted for audio. The extra graphic power will not help (though it will if some bright plug-in programmer feels it’s worth using it for DSP processing) and extra hardware is needed to incorporate many audio interfaces and PCIe cards. I’m sure it will be pretty good for speed, with faster memory etc, but for me I decided to replace my 6 year old 8-core 2.8GB mac with the last of the 6-core 3.3 machines.
On the other hand I’d love to have one for video editing.