What I imagine pretty much is:
-Big conference, no Direct, since they will be showing their QoL platform, in other words, they are showing hardware, unlike last year, so they can't use that they do not have hardware to show to not be present like last year, plus it is not like other 2 are presenting new hardware.
- New info on Both Smashes, reveal of various modes for the Wii U version, atleast 2 newcomers are shown, or one newcomer(Palutena) and veteran(Mewtwo), the 3DS version will get a August release date, and Smash will either be specified for Holidays 2014, or slipped to early 2015, if Zelda U is shown with a Holidays 2014 release date.
-Zelda U trailer, and possible release date, even if it is "Coming 2015"
- Reveal of new Mario, though it could stay to only a artwork or early footage trailer, will have Rosalina, and it will be a Super Mario Galaxy game.
-Miyamoto's new IP, it being one of Nintendo's big NFC games.
- Pokken Fighters, with both regular way of unlocking characters, and NFC figures, something like Pokemon Rumble U
- Fatal Frame announcement for the West.
- The obligatory, X, Bayonetta 2, and Hyrule Warriors trailers. Hyrule Warriors and Bayonetta 2, will get a specific release month, and will be kinda close to each other. Hyrule Warriors being July-August and Bayonetta 2 being September-October.
-Third party surprises, one of them being the port in which Tantalus is working for a AAA game developer. The game will come from Square Enix, and will either be Final Fantasy or Kingdom Hearts.
-Majora's Mask 3D, it is too obvious it is occuring
-Some info on the already known big 3DS games, and if sells don't pick up a big game reveal, if not the reveal will come in the first Nintendo Direct after E3.
-S.T.E.A.M is revealed to be Retro's new project, and we see early alpha footage or artwork of it.
- Though not videogame related, I see the possibility, Miyamoto will announce that his new IP will be his last big work, along the rumor project he has with Retro, and he will announce that he will be retiring soon.
-Sonic Boom info
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