The 5.2.0 version of Komodo Edit has just been released. In addition to some bug fixes and UI features, the release notes indicate that support for PHP 5.3.0 has been added, including code completions for name spaces and syntax coloring of latest keywords (“namespace”, “use”, “as”, etc…).
(FYI, this is the editor I’m currently using, but who knows which I’ll be using a few months from now.)