I think it would be neat if we could capture what happens when you click an option in the menubar. Like the Quit, Minimize, etc. These are OS-related menus, but should still let us decide what happens when we click them.
For instance Quit. On OS X it's under the love menu, on Windows under the icon in the title bar and is called "Close". Right now, it just quits the app outright. Shouldn't it be capturable? So we can show "Are you sure?" dialogs and save the game first, etc.
And Minimize. Well, it'd be smarter if we could detect when the game window was minimized. In case we want to pause the action so it doesn't keep playing in the background.
I guess I'm proposing some functions like love.menuOnQuit(), love.menuOnMinimize(), love.menuOnRestore(), (To go with Minimize) and on OS X, love.menuOnHide() and love.menuOnShow().