Miyamoto held a private round table event earlier in which the question of why there was no Pikmin 3 at E3 was brought up? He kindly replied…

“I’m sorry. Unfortunately we haven’t been able to expand the team size very much, because we’ve been working on so many different games that we’ve shown off at the show. So the team is working very hard, but it’s a bit of a small team…The basic work that they’ve been doing quite nicely….my basic idea is that the sense of the depth of the game and the simplicity of the control will all be there.”

Sounds like Nintendo’s software development teams are a little overloaded. Expect a official reveal at either GDC 2010, or E3 2010.