Well atleast we should get official release dates for Kirby(in Europe), Project Giant Robot, Yoshi's Wooly World, Splatoon, Xenoblade Chronicles X(in Japan), Mario Maker, and Mario Party 10( they said it was coming in the first half of the year or am I misremembering?), which are supposed to come out in the first half of the year and we do not know much about them at all.
The N3DS announcement for the West somewhere before the end pf the Fiscal Year, I'll go with the February 13th rumored date, and Majora's Mask 3D and Monster Hunter 4 will be release titles to showcase the new use of the other circlepad(C-stick was it?). MM3D will also see a limited edition N3DS as every other Zelda game on the regular 3DS before it, and it will be a New 3DS XL. Xenoblade Chronicles 3D will also be formally be announced for the West with a "Coming in 2015" for release date.
Codename S.T.E.A.M will be shown with more story details, new trailer, and N3DS-specific features.
The next wave of Amiibos will be shown for release before E3, most probably including Palutena, Olimar, Lucina, and Charizard.
We will see a glimpse of Retro's new project with the promise of seeing more at E3
A bit of info in game's coming next year, more specifically Devil's Third and Star Fox U.
The Xenoblade Chronicles X trailer will finally show a different location, and some more interesting stuff about the story.
I guess they are pretty safe predictions :/
COMG guide to points: 1 point = Raging. 2 points = Beasting. 3 points = Tearing it up. 4 points = Berzerk. 7 points = Rampage. 12 points = Burst. 15 points = god mode. 20+ points = DIVIDING BY ZERO!!! 40+ points = Youkai (originally Pokemon).
-1 = Negabeasting. -5= NegaRampage. -10 = NegaBurst