Question: When is a blog not a blog?

Vienna: Part of my Blogtalk.net presentation: some blogging tools have started to merge with other tools, like wikis, discussion forums, computer games, and so on. And other things, like my TiVo digital video recorder, are becoming bloglike. As we count blogs and bloggers, is there consensus around a minimum definition? Must the author be human? Must the order of posts on a page be reverse-chronological, or can a blogger organize first by topics, locations, or some other scheme? Please post on this and let me know what you think.