OpenEmu is a Cocoa framework being developed to serve as a wrapper around different emulators. As a result, it can open NES, Genesis, Game Boy, and other games with ease. It provides a standard Mac graphics and control interface so that emulator devs don't have to develop custom ones if they want to create a Mac port. It also interfaces with Quartz Composer, which allows Mac artists and programmers to do cool things with the game's graphics. I thought it would be a good idea to bring this to your attention. Hopefully someone is interested.

Sounds pretty awesome... Is the PCSX2 OSX port too far along for it at this point?

Basically, the problem is gui/emu separation, pcsx2 has its own gui(gtk/x11 for 0.9.6 and older, wxwidgets for 0.9.7 and up) and it's pretty tightly interleaved with the emu code itself, especially in 0.9.7 which is using threading heavily.
Theoretically it's possible but I'll need quite a lot of free time and seeing how I've delayed even 0.9.7 release I don't think I'll look at it in near future

Fair enough!