Even the French dub called it "Black Butler." With a French accent no less.
I've always been a snob for "the original way things are," where "original" translates to "The way things were when *I* first found them" (so, that kind of "it's all about me" snob), but I am discovering that the title Black Butler comes to my lips more easily these days, with the American release of the DVDs, with English dub. Prior to this I clung to Kuroshitsuji without compromise, but when I find a simple phrase like, "Black Butler will be out on DVD in just a few days!" comes out of my mouth and gives me no twinge of, "What did I just call it?", well, maybe it's time I caved. It's good that English-speaking audiences will discover it and an English title helps that. It's not a proper noun, after all. But I keep feeling like the source material will turn its back on me in one collective flounce for the offense.
This, as I'm actually starting to begin learning Japanese, too, beyond just practicing hiragana and katakana over 'n' over. I learned to write fourteen kanji this week!