While I was posting regularly to this site, I had wondered to myself why more spammers weren't trying out contextual spam. After all, they already had bots out there scanning web pages for email addresses, and they already had bots that were trying to manipulate their SpamAssassin scores down by using Bayesian theory in reverse (well, really more of a Markov Chain I guess)...
So it seemed to me the next step was that they would scan in the text from sites where they get the email address, and then use that text to build up a Markov Chain of text for the email.
So time passed and then within the last 6 months I have seen an absolutely huge increase in my spam that is doing exactly this. At first I thought I was just seeing things, but then I started to see enough links to things that I had publicly on the web that it was becoming clear this is what at least one bot system is doing out there.
On the good side, they are doing it very poorly - perhaps partially due to poor programming, or perhaps due to the limits of the data - if it doesn't have much text to build a database on, then it is going to output some fairly garbage data.