From ComingSoon.net ...

Why is William Shatner Not in Star Trek?
----------------------------------------
AMC's SciFi Scanner talked to Star Trek director J.J. Abrams,
who explained why you won't see William Shatner reprising the
role of Captain James T. Kirk:

Q: How do you react to William Shatner's ire at not
having a role in the movie?

A: It was very tricky. We actually had written a
scene with him in it that was a flashback kind
of thing, but the truth is, it didn't quite
feel right. The bigger thing was that he was
very vocal that he didn't want to do a cameo.
We tried desperately to put him in the movie,
but he was making it very clear that he wanted
the movie to focus on him significantly, which,
frankly, he deserves. The truth is, the story
that we were telling required a certain
adherence to the Trek canon and consistency of
storytelling. It's funny -- a lot of the
people who were proclaiming that he must be in
this movie were the same people saying it must
adhere to canon. Well, his character died on
screen. Maybe a smarter group of filmmakers
could have figured out how to resolve that.

Paramount Pictures will release Star Trek on May 8, 2009.

I guess that simply proves that Abrams is not a smart filmmaker. ;-)