Well it'll definately be released in 2010 and it was Miyamoto not Iwata that said it may not be revealed at E3.
I'm strongly hoping it is though and if Nintendo decides to follow in the footsteps of 2006 instead of 2008 then it will be revealed with an epic trailer along with many games due for release in early 2010. Otherwise we'll get most of the 2009 Holiday release list and will probably have to wait for the October conference for the big reveal..
Either way I strongly believe we will see Zelda this year and will play it next year.