Yep. Last good E3 from them was 2014, after that... they were pretty horrible. 

Anyway, besides what's fully revealed, I think it's fair to bet they will announce Super Smash Bros. Deluxe (or something) and the new Fire Emblem (even if they just show a teaser/animation/whatever). Beyond that... we will have to wait and see.

Eh, so they're clinging on to the 3DS still? This plan of their is making less and less sense by the day.

It still has potential to have another decent year, even if its probably the last year of actual support from Nintendo for the 3DS. Why just drop it completely right away when the Switch is still in its infancy. PS3 and X360 got some support even when their successors came around. Funny that we used to criticize Nintendo of completely dropping support of their old consoles the year (or two years) they release new ones. And they said they will continue to support 3DS for this year. 

Well, the problem is that it could keep the Switch from gaining proper traction. If it was the go-to alternative for both home console and handheld more or less right away, it would have a much larger potential market. Then again; there's no guarantee that such a transition would be wholly favorable for Nintendo overall. But it makes me wonder about the whole merging libraries plan, as long as they keep the 3DS, they also keep dividing their developer efforts, and this leads to extended development cycles that plagued the 8th gen for them, and with the expectedly unimpressive 3rd party support and only being a home console extension for now, the Switch might suffer under this idea in 2017 and first half of 2018. If they want any hopes of attracting customers outside of the conventional loop, they need to hit the ground running, devices rarely, if ever, become trendy a year or more into the life cycle. On the other hand; I don't think the Switch will appeal to the mass market to any significant degree.

Long story short; it seems really poorly planned, which is worrying. They're still behaving like a company that doesn't understand the market and its various segments and demographics. We'll see how it pans out, but having the 3DS exist alongside the Switch defeats part of the purpose of having a hybrid console, at least for the handheld segment of the market.

PS: The 3DS is really on its last legs and has been nosediving yoy for some time, I don't know how you define a "decent year", but it could actually be a bad year for it and the payoff for killing it may be bigger than keeping it barely floating.

I hope we'll get at least 1 big new title, like Super Smash Bros or Pokémon.

Switch is seeling great for now and people know that that 3DS is dying (its on its 6. year on market) and it will most likely die next year. They still mention 3DS because it can still sell decent this year too and has huge instal base, but it's very obvious that is dying and that biggest and most important games are coming to Switch, Zelda BotW, MK8 Deluxe, Splatoon 2, Mario Odyssey...and definitely there will some new huge Switch games at E3.

That's actually reason why they saying that Switch is home console on 1st place and successor to Wii U, because 3DS is still selling and Wii U is dead for quiet time now, but you will see how they change their PR talk next year when 3DS dies.

I definitely expecting strong E3 for Switch, I expecting something similar like that phenomenal E3 2014 Nintendo E3. There are so many big Switch games they can show.

All 3 companies must have a big E3 this year. There is simply no room to screw it up this year. Problem with a midgen launch is that Nintendo has to compete with at least one console which seems to be selling great, has an established library and a very bright future for the coming years. Nintendo needs to prove the Switch also has these aspects this E3.

Hopefully they announce MonHun Switch.

I'm not saying the 3DS isn't on its last legs, and yes, I think last year was decent considering how old it is. Though a lot of credit goes to Pokemon Go. Not only did Sun and Moon sell 14 million in only 3 months or so, but XY, ORAS, and even the VC OG games found new life throughout the year as the Go phenomenon became the big news in the second half of the year. Even the 3DS saw a jump, not a big jump, but a jump nonetheless.

And as for the 3DS existing defeating the purpose, I guess the Fire Emblem direct sorta signifies what they plan to do moving forward for now. They not only have a 3DS game coming this year, but also a new mainline title coming next year as well as Fire Emblem Warriors coming on both New 3DS and Switch.

And as for mass market, we'll just have to see as more things are coming within Nintendo's business. Mobile and merchandise are only part of their plans. Of course, the others I'm talking about (ie, films, theme parks, etc.), aren't there in the short-term (1-2 years) future, but can pay dividends later on once they become reality.