No one knows until we start playing Destiny. But in all fairness, they aren't the same genre or story, so it isn't really a answerable question. It will be the same as the "Sony vs Microsoft" war, both have a weak similarity, but you can never really answer it because they are too different. If you are on about sales: then I'm sure Destiny will have a struggle, but will win, as more and more people are playing consoles now.