Essayist vs. Diarist

The New York Times recently referred to bloggers as "web diarists". When I saw this article I immediately reacted negatively -- I don't think of what I do on my blog as being a "diary" -- nor are most of the blogs that I read "diaries." The next day I happened to hear a piece on NPR about the art of essay writing. Essay writing seems to me to be much more like what I expect from blogs. Perhaps the medium has matured to the point where it is valuable to distinguish one type of blog from another -- diaries are certainly one important category, but not the whole story. Diarists, essayists, news aggregators, collaboration venues... each uses blogs as a technology but shouldn't they be distinguished from each other in how we refer to them? Diary blog, essay blog, news blog, collaboration blog?