fps_d0minat0r on 22 May 2014
Sony.
They have morpheus, they have new SKU's, they have tons of AAA exclusives, they have tons of indies, they most likely have PS+ announcements.
I know MS have a lot of games too, but I dont think they will look as impressive as the PS4 exclusives. I know games are not just about graphics but at E3, when you are just limited to watching (unless you go to the event), uncharted will always have that killer effect.
MS may also face EA coming up on the Sony stage and announcing garden warfare on PS4 at 1080p
