Over the years I've become quite friendly with many professional journalists. It's interesting that two of my best friends are journalists and they both have told me, "the only bad thing about becoming your friend is that I can't write about you any more." As a blogger, I don't think I have any trouble writing about my friends if I explain my relationship. The issue of professionalism aside, I think the first person tone of blogging makes it easier to write about your friends in the context of providing information. It's probably much harder or impossible to write about your friends objectively in third person.