With OS X using now the built-in notifications the user should be able to deactivate them easily like on Linux and Windows in Preferences window.
Created attachment 754548 [details] [diff] [review] patch This patch adds only the already existing lines for Linux/Windows to the OS X #ifdef part.
Is bug 879559 a duplicate of this one? Looks like that. I don't have a Mac, thus cannot comment on the interaction with Growl, but have a look at the test for the notification service I mention in bug 879559 comment #2 if it's the right thing.
Comment on attachment 754548 [details] [diff] [review] patch ui-r=me, although I'm starting to worry about the number of things we're adding here, what with the dock options, and all… And the code is simple enough, so r=me, too.