Hello,
I was encouraged (hello, Sumana) to post a Google Summer of Code idea and solicit comments. So here goes.
Perhaps entirely outside of the scope of GSOC, I think it would be a fun project to make wikipedia.org and wikimedia.org accessible over IPv6.
Also, while creating an account to post to
http://www.mediawiki.org/wiki/Summer_of_Code_2011
I noticed that my login was insecure, and that there was no SSL option. Adding a secure login feature would also be a cool project.
Cheers,
mc