Quote - I need to clarify that the Mac will not get the 64-bit editor, only Windows gets the 64-bit editor. There are insurmountable difficulties with a 64-bit GUI on Mac. That's why Photoshop is still a 32-bit app on Mac.

Both will have a 64-bit renderer.

The reason Photoshop is still 32 bit is because it was written with the Carbon libraries. 

Carbon was a temporary fix to bridge from OS9 to OSX.  Apple has been telling developers for almost a decade now not to make long-term plans with anything that uses Carbon. 

They would have to start using the Cocoa libraries. 

If Adobe or anyone else needed any clue it should have been 2 years ago when Apple dropped development of the Carbon 64 libraries.

The "insurmountable" difficulties with a 64-bit GUI are the need to move from the Carbon libraries to the Cocoa libraries.