Nintendo needs a main press conference at E3 2013, all for six solid reasons:
1) NBC, ABC, CNN, Fox News, The Wall Street Journal, USA Today, etc--the non-gaming news sources who still cover some of what goes on at E3--usually focus on briefings from the press conferences, and not so much the show floor. For instance, Sony's PS4 press conference earlier this year got a lot of attention from these news sources. This kind of attention is important towards getting the attention of the millions of non-gamers who do holidays shopping.
More importantly, NO general news source like CNN or ABC follows Nintendo Direct, and few gaming news sources follow much news from Nintendo Direct. It's mostly existing Nintendo fans and Nintendo-centric sources that do. Hosting news via Nintendo Direct is doing little to reach out to people beyond those who already follow Nintendo Direct.
2) Because millions of gamer and non-gamer consumers alike will be seeing news from E3, I'd rather Nintendo give a presentation anyways, just to keep the Wii U upfront in media attention. Even if the media treats the Wii U as a side note, it's still giving it better attention than no real attention at all, since those non-gaming news sources will undoubtedly be about PS4 and "NextBox."
3) Nintendo could also play the situation to their advantage by giving a streamlined, no-nonsense presentation just showing their games. No over-hype talk. No awkward moments in trying to be cute. No waste of expensive flashiness. No two-hour long presentation.
Just a brief talk of future plans and a straightforward showing of their games on-stage, and maybe some gameplay demonstrations of what games are available. That alone would catch some of the media's attention, of how Nintendo cut through all the crap and just give their plans and lineup for the latter-2013/2014 seasons.
4) If the PS4 and "NextBox" reveal a price tag of about $500, which is what some analysts are expecting for the PS4, then the Wii U, along with a confident showing of upcoming games onstage and possibly even the announcement of a price cut, will suddenly stand out as better deal for many shoppers this holidays. Not to mention that if the Wii U can showcase promise, some gamers who've been waiting for a better reason to buy Wii U might pick one up this holidays.
Also, we're all still waiting to see just how the PS4 and "NextBox" operate--neither Sony nor Microsoft have said with directness that their console won't require always-online gameplay, or whether they'll support used games. Sony, after much avoiding the issue when they were asked, said very indirectly that the PS4 can play used games, but they didn't actually directly say that it will.
So, we still have these aspects to think about, and if either of the two consoles sport either of the two problematic features, it'll suddenly give the Wii U an advantage...one that Nintendo will wished they had played upfront on stage with a main press conference.
5) Technically, despite the claim of many saying otherwise, Nintendo does have enough games coming to the Wii U, as well as the Nintendo 3DS, to merit a main press conference onstage. They have the following games coming for them:
Super Smash Bros. (Wii U and Nintendo 3DS)
The Legend of Zelda (Wii U)
Pikmin 3 (Wii U)
Bayonetta 2 (Wii U)
Xenogears 2 (Wii U)
Pokémon X Version and Pokémon Y Version (Nintendo 3DS)
The Legend of Zelda: A Link to the Past 2 (Nintendo 3DS)
Donkey Kong Country Returns 3D (Nintendo 3DS)
Professor Layton and the Azran Legacy (Nintendo 3DS)
Monster Hunter 4 (Nintendo 3DS)
Deus Ex: Human Revolution Director's Cut (Wii U)
The Wonderful 101 (Wii U)
Shin Megami Tensei x Fire Emblem Crossover (Wii U)
Most of those games have sold Nintendo consoles before (such as the Super Smash Bros. and Zelda series), have a smaller but strong following (such as the Pikmin, Bayonetta, Professor Layton, Shin Megami Tensei and Fire Emblem series), been among the best-selling series of all time (such as the Pokémon and Monster Hunter series) and play on games that have been heralded among the greatest games of all time (such as A Link to the Past and Donkey Kong Country).
Xenogears Chronicles on the Wii was praised by many as one of the best RPGs of the last decade, and the sequel Xenogears 2 on Wii U is a big one. Fans of the strong cult classic Viewtiful Joe might find The Wonderful 101 the closest thing to a Viewtiful Joe fix--the game carries a very strong vibe of the Viewtiful Joe, since the two games share the same creators.
These may not be the 25+ games that Sony has announced for the PS3, but it's still strong enough to hold a presentation onstage. These games are strong enough to present yourself with confidence about onstage. Nintendo not stepping up with a streamlined press conference will convey a message of not being confident about these games.
6) If Nintendo doesn't have a main E3 press conference, most news sources are going to interpret the move as Nintendo not being confident enough to step up with a main press conference--regardless of whether that's actually true or not. They're going to view it as Nintendo feeling squeezed out by the competition this year, and taking the quieter road at E3--even though they do have some games to make some public noise about.
In my opinion, Nintendo may be saving money or whatever by not having a main press conference, but they're losing any chance of gaining much notice to those who do most of the holidays shopping--people who watch ABC, CNN, The Wall Street Journal, Fox News, etc.
Remember, it was because of these general news sources briefly reporting about E3 as the reason why the Wii blew up with so much popularity with so many shoppers that year...despite the Xbox 360 and PS3 being vastly superior consoles, tech specs-wise. Wii U is suffering from the general public either bearing ignorance about Wii U or disinterest in Wii U, so bringing up more interest about Wii U onstage might better help with gaining public interest.
There's more reason for Nintendo to go through with a main E3 press conference than not. I just don't see how Nintendo is going to fare very well this holidays 2013 and early 2014 without it.