They are doing this because they had difficulty moving the Titanfall bundle before. If they are having difficulty moving a bundle with their most hyped game, then you have to think about where the system will be just a few years from now. In the short term, this is a good deal your getting. But...
I will wait for the inevitable price drop to $400 before buying. If they are doing sales like this just a few months out from launch, it is a bad sign.