All the latest announcements will be made live courtesy of Nintendo.
http://www.nintendoworldreport.com/news/26271
On June 7, Nintendo will be streaming their E3 Media Briefing through their official event website.
The stream begins at 9 a.m. Pacific, 12 p.m. Eastern at this site, and will be followed by daily updates.
It was really good last year, and considering the site was getting hammered I was actually impressed.