Well this should be fun. I'll start off with Nintendo and edit in some of the others a bit later.
Obviously by this point Splatoon and Steam will be out, and I think we'll be getting a June release for Yoshi's Woolly World and a June-July release for Mario Maker during the Spring Nintendo Direct. I'll admit I really have no clue what the heck Nintendo has in store for the 3DS. My overly asinine bold predictions in, well, bold.
Nintendo
-More Amiibo lunacy; Next Smash Bros. wave, Zelda & Star Fox lines in the works
-More New Nintendo 3DS exclusive ports
-Star Fox Wii U playable on the show floor, named, September 2015
-Xenoblade Chronicles X dated October 2015 in the West
-Zelda Wii U trailer, named, November 2015
-2.5D Metroid 3DS announced, Fall 2015
-Animal Crossing Wii U announced, Spring 2016
-SMT x FE reveal trailer at long last, 2016
-Fire Emblem if trailer, Spring 2016
-New Pokken fighter revealed, Wii U port not confirmed yet
-At least one new IP ala Splatoon/Steam last year
-WarioWare 3DS
-Next Level Games working on F-Zero Wii U
-Pikmin 4 teaser
-Paper Mario Wii U teaser
Sony
-Uncharted 4 trailer, November 2015
-Destiny DLC, as previously leaked
-Gran Turismo 7
-Silent Hills
-Couple new IPs
-Sly 5
-Last Guardian (lol)
Microsoft
-Treyarch's CoD (World at War 2 or Black Ops 3)
-Not a Microsoft guy so, other than that, not a clue
Bethesda
-Fallout 4, Boston, Amazing, You'll Love it, Trust me, Worthy of the hype, October 2015
I tried.