Submitted to ops-help.
Ops forwarded to Atlassian, but I can't read the support ticket.
There's a feature request at Atlassian to restore the ability of anonymous users to view Agile boards, but it seems to have been closed. This is a big impediment for open source projects. Ironically, because jira.atlassian.com itself was recently upgraded to the JIRA 7, they no longer have publicly viewable demos of their Agile boards.
Investigating Trello as an alternative.
The Trello GitHub power-up seems to be useful. There's also the recently released GitHub Projects, but it seems more limited than Trello in several ways.