http://bugs.winehq.org/show_bug.cgi?id=33467
--- Comment #8 from Ken Thomases ken@codeweavers.com 2013-04-28 20:49:12 CDT --- It turns out the change wasn't in the Mac driver at all. WineD3D changed from merely putting a normal window on top to using a topmost (floating) window:
Commit: 6ab0ff5b9d2c681246257787da9f3fa4c9268b95 URL: http://source.winehq.org/git/wine.git/?a=commit;h=6ab0ff5b9d2c681246257787da...
Author: Sam Edwards CFSworks@gmail.com Date: Sun Mar 31 18:25:18 2013 -0600
wined3d: Make fullscreen windows use HWND_TOPMOST instead of HWND_TOP.
Unfortunately, that means this new behavior will be more widespread and problematic.