If nothing is stated about an available or immanent Mac release during SIGGRAPH, demanding a refund would certainly be a reasonable request. Many people (who have been waiting for a year or longer) probably feel similarly.
I have also heard some amusing commentary regarding groups planning on picketing the Pixologic booth. I hope Pixologic is preparing for a fantastic Mac release, or they may want to start preparing for a really angry and vocal group of Mac Non-ZBrush-Users showing up at their booth-side doorstep scaring away prospective customers. I wonder if they will be so easily ignored in person…
I truly hope it is good news for all of us Mac users who want to support this companies endeavors, dished out the dough and have so far, ended up with only a bad tasting silent sandwich made of vapor.
My fingers are still crossed, but not for too much longer…