It's my blog, and I get to determine what is spam and what is not. The latest round of human-generated spam is getting past the automated spamblocks because the comments look valid. They're natural language, often on topic, and occasionally even interesting or insightful - or relevant to the post being spammed.
I'm using a few WordPress plugins to help ease the pain, but for the love of Xenu, this bullshit should not be necessary.
But, if I think a comment is spam, I reserve the right to nuke it. Or to remove the URL and leave the comment in place. It's my blog, and I'm sick and tired of people crapping on it in order to game google. PFO.