They're still using the Nokia Theater (for partners), and they'll be letting select media onto the show floor earlier.
http://www.nintendoworldreport.com/news/34020
Nintendo will host two events at E3 2013, a partner presentation in the Nokia Theater and a media event on the show floor before it opens, instead of their traditional E3 press conference on the Tuesday morning before the show kicks off. Charlie Scibetta, Nintendo of America's Senior Director of Corporate Communications confirmed this in a PR e-mail.
"Beyond the news that will be communicated through Nintendo Direct videos in the run up to E3, at the show itself we’re hosting two smaller events on Tuesday morning before the LACC opens instead of just our traditional one event," Scibetta said. "A media event and a partner presentation will both occur that morning."
What does that mean for us at Nintendo World Report? Well, we'll be getting you hands-on impressions of Nintendo's E3 games right away instead of having to wait for the show floor to open. What does that mean for you as a reader? Nothing drastically different than past years (hopefully), as Scibetta added "While the audiences will be different between the two events, both will occur on the Tuesday morning of E3 (June 11) which is the date and time period the public has come to expect for Nintendo to deliver E3 news."
E3 2013 begins on June 11 and runs until June 13. As of now, we know that Nintendo will be showing off a new 3D Mario and Mario Kart for Wii U. The new Super Smash Bros. will also be shown off in some capacity. Additionally, we'll likely see demos for The Legend of Zelda 3DS, Mario Golf: World Tour, Yarn Yoshi, Yoshi's Island 3DS, and the variety of announced and unannounced games Nintendo has lined up.
See below for the full quote from Nintendo of America:
"As you’ve already seen, a lot of news about Nintendo games and services that traditionally would be held until E3 is being delivered this year through Nintendo Directs, and various press events. This approach will continue between now and E3. No matter where you are in the world, you’ll be fully informed. We look forward to continuing to provide you with Nintendo news and content in ways you haven’t before experienced. Beyond the news that will be communicated through Nintendo Direct videos in the run up to E3, at the show itself we’re hosting two smaller events on Tuesday morning before the LACC opens instead of just our traditional one event. A media event and a partner presentation will both occur that morning. While the audiences will be different between the two events, both will occur on the Tuesday morning of E3 (June 11) which is the date and time period the public has come to expect for Nintendo to deliver E3 news.
At the Nokia theater we’ll meet with business partners (retailers, publishers, analysts, etc.) from the NOA territory and discuss our plans for driving the business and providing tailored information that this group finds useful to their operations. Nintendo has done these same type of business meetings at past E3 shows, but has not in the past few years. This year we are returning to that business partner meeting format. New this year at our booth in the LACC, prior to the show opening, we’ll invite a small group of media to play our games. We will have a strong line-up of beloved franchise experiences available for immediate hands-on play. We are continuing to consider exciting new ways to bring the news of our games and information directly to the players at home during the E3 timeframe, and will have more to say about that at a later date."