Is someone who was killed for being Jewish without having been given a choice to save himself by transgressing the Torah, called a kodosh?
There's a Rabbi Rakeffet mp3 on this on yutorah.org (sorry no, I can't tell you which one).
It's widely circulated that the Rambam wrote that anyone killed simply because they were Jewish is considered to have died "al kiddush Hashem."
However ... we don't seem to actually have such a written source in the Rambam.
Post-Holocaust, the subject came up a lot. There was one scholar (pretty sure it R' Shlomo Zevin or R' Mendel Kasher) who in fact wrote that no, they're not. Most other rabbis who addressed it said that yes they are, this rumor must have come from someplace, and that's how the Jewish people have accepted it. (I believe the Seridei Aish is in this latter category.)