I think blkmage sufficiently answered the original question, but I do just want to point one thing out:
blkmage wrote:Why? Why would you need kanji subs when no one who's reading subs can read them?
For quite a few people, it isn’t totally pointless to have subs in kana (hiragana, katakana, and kanji). I’ve been living in Japan for over four years and am conversational in Japanese, but even now if I watch untranslated anime, I will typically only understand about 50% of what is being said (partly because the vocabulary used in anime often differs substantially from what I use in everyday conversation). So, even though I know some Japanese, it’s not superfluous for me to watch English subs, and having subs in kana is
extremely helpful for learning Japanese. Even if I am watching an untranslated region-2 DVD, I will always turn on the Japanese subtitles when available for this very reason. Also, romaji are a hindrance to one’s progress in Japanese and are obnoxious to those who have already learned kana.
And although I use myself as an example, I think the same principle applies to pretty much anyone who has studied enough to have learned some kana but who has not yet attained native-level fluency. I do realize that having three different subs at the same time during an OP or ED is messy and excessive (I’ve seen some like that myself), but subs in kana actually are very helpful for people who are learning Japanese. There’s quite a bit of gray area in between people who don’t read any kana at all and people who have attained native-level Japanese fluency, and kana subs benefit everyone who falls into that category.