E3 2014 is going to be a very important event for Nintendo; they'll have to gain an audience for their dwindling console as well as win back some of their hardcore demographic. Nintendo has fans who will go to blazes and back for their beloved company, and it's no surprise. Mario, Zelda, Metroid, and Pokemon are all household names that are still relevant and successful to this day. However, Nintendo has yet to regain its influence on those who just casually enjoy the medium.
Most consumers just don't see themselves buying a Wii U anytime soon. Much like its predecessor, the hardware has received some scrutiny for its unorthodox controller, lack of third party support, and graphics that are inferior to the competition. However, while the Wii managed to find some success with its innovative motion controls and solid first party titles, the Wii U has yet to even come close to matching that. With its declining sales and lack of killer apps, some have called the Wii U a lost cause, which is rather disconcerting given that it's been out for two years. The PlayStation 3 had a rough start during its first year, but managed to receive some financial success once it acquired an attractive price point and solid exclusives. This has yet to be the case for the Wii U.
As for their foray in the mobile market, Nintendo has gained some controversy over their omission of gay marriage in their simulation game, Tamagotchi Life. Nintendo apologized and promised to be more inclusive with their future titles, but the damage and negative publicity had already been done. Hopefully this will have minimal effects on the game's sales.
This not to say that Sony and Microsoft have nothing to worry about: both have received controversy for their lack of backwards compatibility and emphasis on social networking. The Wii U has the advantage of being backwards compatible with Wii games, but not GameCube games. For health reasons, Nintendo's president Satoru Iwata cannot attend E3. This is most unfortunate, as Nintendo needs all the support it can get to push their console and their games.
All is not lost: Mario Kart 8 was a massive financial and critical success. It's very likely that the next installment in Nintendo's popular Smash Bros series will continue that streak. Bayonetta 2, the sequel to the well received Bayonetta, is being published by Nintendo and released exclusively to the Wii U. Bayonetta has an established fanbase and if the sequel is as good as its predecessor, then Wii U owners will have something to brag about to friends who own an Xbox One or PS4. There's also a rumor that Ninendo will take the Mario series in a similar direction to Sony's Little Big Planet franchise: a new installment that allows players to customize and create their own Mario Bros levels. If this is true, Nintendo could win some costumers who were big fans of the Little Big Planet games, which have garnered critical acclaim and great sales. However, while this may be enough to alleviate Nintendo from their current problems, they'll have to come up with some solutions that are more long term.
It's hard to think of what the industry would be like without Nintendo, but if the company can't adapt to compete with the likes of Sony, Microsoft, and potentially Valve, it'll most likely become another Sega or Atari.