I posted a reply in a previous thread about this, but if we're being loud, I thought I'd have a voice in here too.
I think it's a great idea, and would be VERY beneficial to people who are too busy to code something themselves, or simply don't know how.
The only problem you'd be running into (which I think was mentioned), would be people using code snippets purchased in "CodeCave" (nice, btw!) in themes on ThemeForest.
There would have to be some sort of way to allow a themer to use the code, while still providing credit (and $credit) to code snippeteer. Then, this same system could be moved to GraphicRiver, etc etc.