First, why do you care if they're GPL, or more generally a "copyleft" license? As long as they're under a OSD-compliant or "free software" license, they should suit the mentioned purpose of standardizing across open-source OS distributions, and the fact that someone can make a proprietary derivative doesn't really seem to matter to that end.
Second, right on the front pages so conveniently linked by MartinK... 3 minutes of poking at the FSO site turned up nothing definitive (I'd guess license varies by package), but there is a Licensing proposal in the wiki.
Good thing someone happened by with a web browser and enough time to click through those links, or I guess you'd still be wondering...
The content on that page is a bit ancient (written back in 2007 and not updated since that day apart from general wiki gardening). See */COPYING under the cornucopia tree - summary: a mix of GPLv2 and LGPLv2.1.