Might as well update my prediction from 3 months ago. Only doing MS right now.
MICROSOFT - 90 minutes
Rise of the Tomb Raider demo
Gears of War Remastered
Black Tusk Gears of War teaser + Beta with GoW:R
Scalebound in game trailer
Forza Motorsport 6 trailer
Lionhead new IP tease
Twisted Pixel new IP tease
Fable Legends trailer
Quantum Break demo/trailer
Joe Montana 2016 reveal trailer + gameplay/reasserting they have an NFL deal
Crackdown 3 in game trailer
Phantom Dust re-reveal trailer
Halo Wars 2 CG/Gameplay trailer
A new IP gameplay demo
Halo 5 campaign demo + BTB footage
Rare 30th anniversary extravaganza
Killer Instinct Season 3 announced
WITH SPECIAL GUEST APPEARANCE FROM THE BATTLETOADS
Banjo Threeie announced and Banjo 1+2 double pack released on Xbox One store
WITH SPECIAL GUEST APPEARANCE FROM THE BATTLETOADS
Conker Project Spark Episode 2
WITH SPECIAL GUEST APPEARANCE FROM THE BATTLETOADS
Battletoads
WITH SPECIAL GUEST APPEARANCE FROM THE BATTLETOADS
Division gameplay trailer
Just Cause 3 gameplay trailer
Indie Reel featuring 25 games
Black Ops 3 demo
Madden 16 trailer
R6: Siege trailer
AC:S trailer
2 existing 3rd party IP
1 new 3rd party IP
Hardware/Bundles
Hardcore Xbox One controller with share button, reworked bumpers, and 2 paddles on the back
Madden + Joe Montana bundle
Halo 5 special edition console reveal
1TB revision
Windows 10 update
June update will be talked about here
Faster and more responsive UI
Universal apps talked about
Excel on Xbox (Megaton)
Avatars back in action
TV!
Halo Spielberg series finally talked about that'll lead into Halo 5
Phil Spencer says that Xbox is in a better place than where it was last year and that the fans are great and that Gamescom will have even more to show
First to third party ratio - 19:9
I'd be pretty hyped if MS were to do almost all of this.
Realistically less than half of that will show up. Sony showed about 20 games in 2 hours. There is no way they will do 28 in 90.
Since a lot of those game were announced last year at E3 they need extensive gameplay sequences of about 5 minutes each.
Rise of the Tomb Raider demo and PC launch the same time as PC.
Gears of War Remastered
Black Tusk Gears of War teaser + Beta with GoW:R
Scalebound in game trailer
Forza Motorsport 6 trailer
Fable Legends trailer
Quantum Break demo/trailer
Joe Montana 2016 reveal trailer + gameplay/reasserting they have an NFL deal
Age of Empires 4
A new IP gameplay demo of Rare's new game
Halo 5 campaign demo + BTB footage
Division gameplay trailer
Just Cause 3 gameplay trailer
Indie Reel featuring 25 games with a number of them announced last year.
Black Ops 3 demo
Madden 16 trailer
R6: Siege trailer
I might be over doing it as well. Some have to be left until Gamescom.