There are a lot of PHP frameworks out there but has the offer grows the quality or funcionality seems to miss a bit in everyone.
At the end I still do not know witch is best and don't have time to try all, recently I've been using cakephp for a few months now and still discover new things to do with it and have to go around and discover how it all works in the framework.
If a system for localization would be in place in this framework ( or other ) I would have to code around it, so it would work in with other code. Like smarty wich has a workaround for cake, yet all this solutions are still showing up, and at the end we have to insert all this in the framework and sometimes it doesn't work that well.
The positive side is that when someone comes and picks up the code he will know how it's structured and can pick it up right away.