If you ask me, simply being under development when the game is not even done is quite an accomplishment. They are proceeding very quickly for the mac/linux scene.Windows XP
Firefox 2.0 / 3.0
Internet Explorer 7 / 8
Support for Mac & Linux, along with alternative browsers is under development.
Its hard to compare the stall of Epic to the progressiveness of ID when it comes to mac and linux. "shit or get off the pot" is a good statement for Epic. If you can present some evidence that ID is going to flop on QLive then please present it. All that seems to have hit me in the head so far is that good chances are mac/linux support will come shortly after the release (a few months). I see no reason to flame a company that has not broken any promises.
Maybe it wont come out. Who knows. But I personally will judge the character of a company on its past results over its rumors and skeptics. I am not a stock broker and don't intend to play one.