I think Eindhoven (Netherlands) has a lot of the points that would make a GOOD city. It is still growing and (occasionally) failing; but at least it is trying to become this "new" kind of city where work and living go hand in hand, and where everybody is an "actively participating citizen".
This is also the area where Eindhoven is interesting; we have this huge old factory area called "Strijp-S" that basically serves as an area to experiment with new forms of working and living. They'll be working on this until 2030 or so, but the nice thing is that residents and city planners are working together on this. The more you contribute, the higher the chance that you'll eventually get your own designed home.
Next to this, the old factory buildings are already actively in use to house all kinds of collaboration initiatives and startups.
We also a some defining moments, namely the Dutch Design Week ( http://ddw.nl/index.php?lang=en ). It's pretty big event with room for everyone to talk about design during all kinds of workshops and discussions as well. I'm not an expert on this, so I'll go find some people to back me up on this one..