can blog spam be solved like email spam?

i saw a great posting on the long tail blog about how we might think about blog spamming. before starting this blog, i had no idea there was such a problem known as blog spamming; after reading through some of the comments here, i'm all too familiar the symptoms.

to help alleviate the problem, i see blogger is already implementing the "nofollow" tag on all links left in comments. i think that's an awesome first step. next, i see blog hosts putting up other defenses, similar to the multiple e-mail spam detection systems in place today. as anderson puts it, this is the low hanging fruit and i'm glad to hear that six apart already has solutions under way.