It's an intriguing prospect. I am assuming you're referring to the revision where the bug was discovered. For example, I might have a defect that's been in my system for years, but didn't know about it until release 2.1.0 came out.
It's not hard to do, and may be useful. I've never done it myself. I'd say give it a try and report back how it works. This is usually something that the defect tracking system does quite well, but maybe embedding this in the Subversion logs might prove useful. -- David Weintraub qazw...@gmail.com