Even now I'm always amazed, just how many idiots are on the internet ... Someone makes a thread, based on baseless some daydream, and it's guaranteed, that someone else will turn up to re-discover it again, and again, as "the one truth" ...The author should be ashamed, take a look at this thread:
http://forum.onemanga.com/showthread.php?t=91178
@FakeHero
No, WH is not plagiarism, and it's not like Bleach, FMA, or the others are unquestionably original works. Each and every work has it's root in others: it's the nature of literature. If you don't see the works a manga based on, it's just means you didn't read enough books yet.
When you draw manga, each and every picture comes from somewhere. It may be a picture taken, a scene from an other work, a painting, an illustration, or something else. Pieces from the scene may come from different places, but the scene itself is original. If I were an artist, and if I were to saw a cool scene somewhere, I'm damn sure, that I'd like to include it in my work too, and that's what you call "inspiration by other work".