Although his appearance definitely adds another level of intrigue, I kind of wish that Byakuran would leave. It's like, bro, we've just finished some crazy long arc all about you, please get out of here for at least a few more chapters.
As stated earlier, I really hope that Byakuran doesn't heal Yamamoto all Genkishi-esque in a sort of "I sold my soul to the devil" moment. Yamamoto's a pretty solid guy, so I don't think this will happen, but meh, you never know.
Also, I can't be the only one eagerly awaiting some ridiculously b.a. Hibari moment; I mean, it's inevitable.