3. I can't wait to find out what code causes this, and hope that I understand enough to grok why.
2. I have a website that displays historical changes (diffs) between things, and I noticed it was displaying "blockquote" for no reason there.
3. Me too!
What version? I'm running 25.0.1364.172m on Win7 and I see nothing unusual. Edit: "Dev" and "Canary" builds are v27 and both have this problem. "Stable" and "beta" are v25 and don't have this problem. Sounds like a job for git --bisect :)
4 different people on Chrome 27 confirmed it gets replaced by 'blockquote'