The Zürich community has been quite active (200+ Slack contributors, 40+ gateways). Started by @gnz, we used the @iotzh Meetup (1000+ members) to bootstrap the community (and still organise LoRa meetups regularly).
As a next step, 23 partners founded the "Open Network Infrastructure Association".
Why an association, if TTN is open source? Through this step we hope to be able to share costs/rewards of running an open IoT network in the long term.