In the handy FAQ, it is rather confusing since it says that " Technicallyall of the art on this site is legal for use in commercial projects -- however, some of the licenses require you to distribute the source code of your entire project for free," ... yet in the following descriptions of each license, none of them say if they require the project they are used in to become open-source.

http://opengameart.org/content/faq#q-proprietary

HOWEVER -- I see that a better version was being made here several months ago http://opengameart.org/forumtopic/license-question  on April 20th (the later version in that day seems the best).

It would be very nice if this were updated in the official FAQ. You really have a fantastic site by the way :)

Thanks