I was being interviewed today for an article on using blogs in the classroom (my first interview, very exciting) when the reporter asked whether or not I felt having students identified by only their initials hurt their sense of ownership or voice. I hadn't considered that aspect of the identification issue before.
Upon reflection, I don't think using initials instead of first names makes a difference for my students. At least, I see their personalities, their voices, in their blog enteries, but I do have the advantage of working with them every day. As for ownership, I'm still not sure. I need to ask them.