The problems the author describes aren't limited to just hackathons. Developer-entrepreneurs are constantly bombarded with requests for free labor from idea people. Don't code for free!
I talked about that one a few years ago too: http://caseysoftware.com/blog/startup-risks-for-developers
Would be even better if your site had some TLS love! ;-)
Thanks for sharing!
If you're really lucky they'll offer to split any income with you 80:20.
If not - think of the exposure! (Etc.)