Dave Dribin has released a new version of MAME OS X for you Apple users out there. Changes are as follows:

Upgrade to 0.116 core.
Fix aspect ratio for rotated displays.
Save and restore audit results. (Thanks to b.bum)
Enable dynamic recompiler (DRC) on Intel.
Ignore HID devices that could not be open. Should fix Wacom tablet issues.
Assume square pixels if display size cannot be determined, i.e. a TV.
Add Help menu item to show core whatsnew.txt.
Fix Command-T throttle so it works, again.