I was supposed to do this ages ago but... Here it is. Because Arlo reminded me with his video x3

I also feel like a psychic because I predicted the Pokemon Direct flawlessly.

Obvious ones out of the way:
Super Mario Odyssey
Splatoon 2
Probably some promo on the fact that ARMS comes out after E3 (I don't think they are going to talk about it)
Online Service and Voice Chat App (Maybe more games than Balloon Flight, Mario 3 and Dr Mario)
Hey Pikmin!
Pokemon Ultra Sun and Ultra Moon (I don't think much is going to be shown for this one)

Predictions

. I think some apps like Netflix, Youtube and maybe some social media stuff is coming. Maaaaaaybe Twitch?
. They will probably show off that Mario x Rabbids game. (Maybe at Ubisoft's panel instead)
. 3rd Party support like Fifa 18, Skyrim, Jackbox Party Pack 4 and Dragon Ball Xenoverse 2.

Now for the exciting ones:

. I predict that we will get a Mario Party revealed. I don't think it would be a Mario Party 10 Deluxe. (Because it didn't do that well apparently) Mario Party 11 is more likely.
. I agree with Arlo on Wario Ware Switch. I think the Switch will be a Party Game Machine. At least I really want a Wario Ware. But I do think we will get one eventually, maybe not at the E3 though. BUT I will throw my two cents at it.
. Some kind of Platinum Games hack and slash. I am thinking maybe a Wonderful 101 2 or a compilation of Bayonetta games. Or maybe a new thing!
. The big reveal will be Animal Crossing Switch with Amiibo Support where you can have other Nintendo characters as NPCs.

Negatives

. I do not think we will see Smash 4 Deluxe in this E3.
. No Metroid.
. No F Zero.
. No Mother 3 x3

Maybe a boring list but I tried to make it A BIT realistic. Want to hear what you guys think! <3 Also I know I got risky with some of these but I feel like you kinda have to be with Nintendo.

Edit: Completely forgot about Xenoblade and Fire Emblem Warriors, I don't think they will get much but maybe something!