For this year's presentation, Nintendo will be broadcasting the event from here, their E3 Facebook page. As long as the server doesn't crash from so many people tuning in, that should work.
But just in case it does not, the video will also be broadcast right here! On Tuesday morning at 10am MT, the space below will also be a broadcast of the event. (Although, you should know that the comments being made on there, if any, have nothing to do with me or this site)
Update: Sorry folks, but I was unable to
So there ya go! You have no excuses why you can't watch this year's presentation. And it should be a good one. Launch games for Wii U, new games for 3DS... I can't wait! See you then!