I like Kohana much more than CI, if only for tossing PHP4 support.

However, but I've found that there is lots of fragmenting in the community/documentation. See the differences between 2.3.4 -> 2.4 (lots of breaking changes) -> 3.0 (almost entirely different framework). Which is kind of a bummer when using it for long-life projects (we have a few projects are stuck on 2.3.4).

That said - Symfony 2.0 looks fantastic, and very much like the next "Rails-like" PHP framework.