They are holding a vote to which new feature will come next.
iPhone and Blackberry have the same # of votes.
This looks like a really promising application, let's vote to make our blackberries the next developed client!
You can vote here: LastPass Forums • View topic - Vote For What New Features are Most Important To You
It seems they will do iPhone first unless the blackberry universe tells them otherwise.
See here: LastPass Forums • View topic - Any chance for a Blackberry client anytime soon?
But then if that convinced you we need to change their mind vote using the first link.