Hi,
During a Wikimania you get the best ideas for the next event so why not saving them right then? For Wikimania 2008 I just created the public page
http://meta.wikimedia.org/wiki/Wikimania_2008/Whishlist
where everyone can add whises and suggestions instead of sending them to some mailing list where they will be forgotten anyhow. I am sure that there are already similar lists in other previous Wikimania's wikis but the list needs to be directly linked to Wikimania 2008 page or organizers of Wikimania 2008 will not stumble upon it.
Greetings, Jakob