Open Source Wiki

So lately, I've been thinking about open software. For starters, I'm going to switch to Ubuntu Linux when I replace my hard drive over break. Also, I've been thinking about starting a wiki for GPL software development. That is, I download the wiki software, set up a server, and make a few tweaks like section editing on loops, a "download it!" button, etc. I'm aware of Wikisource, but the code there is public domain, not GPL, so I can't just take preexisting GPL code and add it. I'd want to to take full advantage of the momentum the GPL has already gathered. Not that I've got anything against BSD, but it's not shiny enough for me.

Some things I'm pondering before I start the project...

• What legal issues might arise out of this?
• How might I address the security weakness of public wikis? I'd imagine that people wouldn't be willing to run programs that had malicious code some scum added on.
• Has anyone tried this with GPL code yet? If so, how did it fare?
  

How viable do you folks think this idea is? Any suggestions?

UPDATE: Apparently, contributions to Wikisource are under the GNU FDL, not the public domain. Unfortunately, the GNU FDL is incompatible with the GNU GPL used by Linux. I'd want the whole site to use the same licensing scheme, so project code snippets could be quoted in discussion and then moved back, etc. So now, I have even MORE questions!
Can I license non-code discussion pages under the GPL? Can I just slap a dual license on the discussion pages?

I like the idea, but this red tape is giving me a headache.