My experience has shown me that the "Mac creative crowd" is typically not the "programmer" or "dev" crowd. The 2% Niche market of Mac users tend to care less about anything that involves code let alone a right-mouse button.
This is why the Mac tends to dominate in the design or graphics related fields.

If there is any debate about what to port GS over to, I think the energy would be better spent on solutions to output from PCs to console game formats.

Mac users that do program, can buy a copy of Virtual PC running windows XP and use the existing Gamestudio software on their Mac.
Virtual PC Software