Well, looking at the Xbox 360 and PS3 makes me guess the Xbox One will have timed exclusives at the start and then there won't be any interesting exclusives, just uninteresting crap, while as the PS4 will end up getting some of the previously-exclusive Xbox One games and Sony will push new exclusive IPs that are way more interesting that what the Xbox One offers.
Microsoft doesn't seem to push for 1st party exclusives as much as Sony and I expect a bunch of Xbox One exclusives to also release on PC (they have already announced at least of their "exclusives" will be on PC too).
Also, as I said, the Sony systems get more interesting exclusives. I mean, I think about it and I see like... Gears of War vs Tokyo Jungle. Gears of War is one (or maybe the best) cover-based TPS but that's it. Not so interesting or unique, while as Tokyo Jungle is super unique. I guess it boils down to Western vs Japanese, in a way, since Japanese companies seem to supporting the Xbox systems less and less and time goes on (and the Japanese make the best fighters, so they've won me over just with that)
But regardless, most big games will be multiplatform anyway.