Spam filtering

Are there any plans for adding options for spam filtering, particularly for comments by guest users? I'd like to use cactus comments for my blog, however I've managed to attract the attention of some unpleasant types who like to spew vulgarities, harassment and hate speech in my comments, and I'd like to prevent such comments from showing up in the first place as much as possible. A bayesian spam filter has proven sufficient in my personal use case.