CodeIgniter is still PHP4-friendly. It's not "hot" by any means. CakePHP is still actively developed, but it's pretty miserable. (It's slow, too - so much so that framework devs usually benchmark against it because it's so reliably slower-than-everyone-else.)
If you're going to use PHP, I can't really think of a good reason to use anything other than Symfony2.
If you're going to use PHP, I can't really think of a good reason to use anything other than Symfony2.