[mdolon]

Almost - the GPL wouldn't apply to the CSS, JS or HTML of his themes, nor would the GPL nullify trademark and copyright. Still doesn't mean that his claim would hold up in court but it probably wouldn't be completely hopeless either.

[BobbyH]

In addition, if I purchased the Thesis theme, although the GPL would give me the right to redistribute it, I would not be able to market my redistributed theme as "Thesis", presuming that Chris has trademarked that mark.

So if I tried to redistribute the theme as "Thesis", Chris could (1) sue me for trademark infringement. He could also (2) file a DMCA claim against me (or sue me for violating his copyright), if my product included his copyrighted CSS/JS/images/etc.

These remaining trademark and copyright protections are why Matt asserts that applying the GPL license to the Thesis theme would not hurt Chris' business.