I've been collecting bits of feedback from this mailing list and from some of you in person last week. We have also just put up a Feedback page at:
http://wikimania2013.wikimedia.org/wiki/Feedback
The London 2014 team is also soliciting input and ideas at:
http://wikimania2014.wikimedia.org/wiki/Brainstorming
Thanks, Ellie
Ellie Young Conference Coordinator Wikimedia Foundation