I organized and facilitated the Copenhagen Startup Weekend which just ran in April and it beat all my expectations. We had 112 participants (including a lot of high caliber people), 40 of whom made one-minute pitches. Of these 40 the crowd picked 12 around which teams were formed. The mentors and jury on Sunday evening jury blown away by the progress teams made. I know of at least 3 teams which are still working on their projects - keep an eye on http://www.memolane.com who won the cash prize and are about to launch. See http://www.copenhagen.startupweekend.org for a sample of the ideas and participant feedback. Also see http://vimeo.com/10870013 to get a feeling for the vibe at the event.
Just edited the first issue of the Copenhagen edition. Great response so far; people like the simple and readable format and the overall 'spirit' of the initiative.
I read the Silicon Valley edition, just to drool...
We're definitely doing it again in the fall!