I've just enabled guest commenting on my blog. It hasn't been turned on until now simply because Geneone wasn't equipped to allow non-registered users to add comments. I'm hoping this will make it much easier for people to leave their comments and thoughts on entries.
It'll also be interesting to see how long it is before I get some automated comment spam. I suspect the fact that I'm not running a popular blog software makes it harder to get spam as many spam bots simply request wp-comment.php directly.