Speaking of such.  I wont include vague predictions since a few things has already been confirmed like Gears 1, Rare announcement, and Press Play New Ip.  Im sure most of these will be wrong :P

 Halo 5 Campaign Reveal

 Rise of the Nations Cross-platform

 Rare MMO RPG Cross Platform Press Play 3D Platformer  Crackdown Showing off the Cloud Cross platform 
 Gears of War Summer Release  Gears of War 4 Sequel not prequel  Exclusive Content for Fallout 4  Mass Effect 4 Exlcusive Content  Killer Instinct Season 3 Teaser
 Banjo-Kazooie 3 (Though i think maybe Gamescon)  Halo Wars 2              Blank  Minecraft Hololense Gameplay State of Decay 2 Reveal
Third Party Moneyhat EA  Scalebound Gameplay  Battletoads Outsourced  Mass Effect 4 Gameplay Reveal  An indie montage
 Windows 10 + Xbox Talk  Phil Spencer Wears Banjo shirt  New Studio Announcement with New Ip  Something Assassin's Creed will be shown  Call of Duty Blops III Gameplay