Ok people stop panicking! 
Since when did they say 3.5 is not going to happen? 3.12 is an interim release for Mac users paving the way for 3.5 on both PC and MAC. That’s still going to happen.
As I read Auricks post about 3.5 more info will be offered as and when they can offer it. As it happens that latest info was 3.12! get it? good!
As a programmer I understand totally that you cannot always predict how a product release will go. Just trust me when I say that Pixologic are dealing with the most hideous of programing tasks both in maths and programming efficiency terms, not to mention cross platform issues that will ruin the efficiency of ZBrush if done wrong.
Big pixels I’d suggest you email support directly if you’re concerned. They totally understand how frustrated Mac users have been and I guess they thought 3.12 would smooth out a few frustrations. You can’t please everyone in this game but with any luck this will mean dual releases on PC and Mac from now on.
EDIT:
Why? As the 3.5 post said in the Questions and Troubleshooting forum:
ZBrush 3.5 will be a FREE upgrade to all registered users (PC and Mac).