Netbeans 6.5 is going to be a great IDE for PHP; if you haven't tried it yet, I suggest you to try it now (and also have a look to the dev. blog: NetBeans for PHP : weblog)

For the future versions Netbeans PHP will include official support for the most voted (and hopefully, the most popular, anyway) php frameworks.

You can vote for your own:
NetBeans for PHP : weblog

Here are the instruction provided from the symfony community:
symfony | Web PHP Framework | Blog | Support symfony inclusion in NetBeans

And the direct link for vote on issuzilla:
Issue 146028