Someone asked me today: if talk about is cheap, «what would the action be?» Great question, always worth asking oneself. So here's what I answered about my last 18 months.
As for action within my reach, I improved installation and upgrade docs, I maintain the MediaWiki 1.X pages to make them look interesting, I compiled a list of reasons to upgrade, I scraped the web to find tens of thousands wikis to monitor on wikiapiary, and finally I sent tens of thousands emails to complete strangers to tell them to upgrade, receiving perhaps 150 replies.