I've just released a preview of ScalaMock 3. Instead of all that fiddly mucking around with compiler plugins that ScalaMock 2.x required, it now uses macros (thanks, Eugene et al!).
It's not yet quite as capable as ScalaMock 2.x (for example, it can't yet mock singleton/companion objects or object creation), but it is functional enough to be useful, I believe. And I've gone far enough to be convinced that macros are going to be a more fruitful long-term approach than continuing down the compiler plugin route.
There's a writeup with examples on my blog:
I'd be very grateful for any and all feedback, especially bug reports.