It's gonna be expensive, but for some who require tonnes of VI's, tracks and FX processing at high sample rates and low-buffer settings, I've a feeling it's gonna be irresistible, especially if video editing forms part of their workflow as well.
If you're just a lowly Kemperite, think of how many tracks you'll be able to record, overdub and play back at high-SR and low-buffer settings.
Mac Pro - Technical Specifications