Zak: I’m not an expert on this by any means, although I guess I’ll take a shot at this. The definition that I’ve most often heard attached to queer is anything that is not heteronormative. I don’t think that being a straight trans* person necessarily excludes or includes someone in that definition, and that it is their call. In that sense, I do not thing it is appropriative for them to use that word. Queer is much more than just who you are attracted to or who you date, it’s often taken on as a political identity. From what I understand, part of the whole point of queer is that it is about openness and fluidity instead of strict boundaries.
I guess by some people’s definitions I would be a straight trans* guy, and I identify myself as queer, so I’m a little biased in answering this. This is just my opinion, though.
Adrian: I agree with much of what Zak has to say. I think that another aspect to being queer is having a non-linear history of your identity, or some aspect of your identity. I think that transpeople embody this aspect of being queer, all of us do. I’m not saying that we all have to identify as queer or claim the word affectionately, but we should all have the option to do so if we please. I understand that appropriation is a bad and hurtful thing and we should all be mindful of the damage it can cause, but I really think that this may be pushing it too far. Identity policing is also a bad and hurtful thing. Echoing what Zak said, I am read as a straight linearly-male (having always been male) person, but I am most certainly queer and I identify as such passionately.