I too have been seeing an increase in blog spam at some of our sister sites, especially those using Wordpress. Akismet, an anti-trackback spam group, is confirming the case in their own stats too. It looks to me that the spammers have declared a new war on many fronts. My theory, there are a lot of lonely servers on the University campus in the United States that are just sitting there now that the students have gone home for the summer.
There has been a ton of buzz around the blogosphere about the huge spikes in spam the past few weeks, and we've been blogging about it a fair amount too, but I was getting tired of blogging the doubling every few days.
Now we have a pretty neat Akismet stats page which graphs out the number of spams and legitimate comments (aka ham) that we see each day. Check it out and be glad you're not having to deal with all that by hand any more.