Bleach is still an ongoing manga so they might pick it up again in anime. Even Code Geass. Code Geass hasn't ended yet, they still make it.
As for One Piece, it's about to get really good in the next 2 or 3 episodes. Also, the english voice actors were chosen by the person who made One Piece.
See, it's still ongoing.Code Geass: Renya of Darkness
Written byGoro Taniguchi
Published byKadokawa Shoten
DemographicShōnen
MagazineShōnen Ace
Original runMay 26, 2010 – ongoing
Volumes5 (List of volumes)
The voice actors change because 4Kids went out of business and when Funimation licensed it, the creator of One Piece came and did the auditioning.
The way how anime works is that the original format is Manga. And then the manga turns into anime.
http://www.mangareader.net/
If you search any anime, it'll show up and you can read it picture form. Code Geass and Bleach are still an ongoing thing, it's just in manga form. If it gets popular, they'll make an anime for it.
See, it's still ongoing.
That's because most English anime is licensed by Funimation. Dragonball Z was dubbed by Ocean and Funimation, Naruto, Bleach, all of them are done by Funimation.
Look at the guy who voiced Goku and how many other voices he did.
http://en.wikipedia.org/wiki/Sean_Schemmel