As mentioned in Knut Urdalen's latest blog entry, the folks from Waterproof Software have announced a new extension that will be included with their upcoming version of PHPEdit (2.12) - "a Prado extension for syntax highlighting, code insight and and code hint".

This combined with the PHPUnit support in the same upcoming versions should make for quite the powerful tool. Check out the posting if you want more information on being a beta tester.