While there are people who have been very active in the Zabbix community, it might not be so easy to start participating, especially if you are not frequenting IRC, which is the main Zabbix community hub. Hopefully the Zabbix community platform – Zabbix.org – can help here.
One of the promises of Zabbix is an ability to monitor pretty much anything. That is possible using various extending capabilities on the Zabbix server, binary agent and elsewhere. Maybe we can monitor some aspects of Zabbix community using Zabbix itself?