From the article you posted:
"Of course, mid-May in Google-speak may mean who knows when, so maybe everything's okay after all?!"
He's right about that, Google is almost never on time for anything so in this case that's good news. XMPP could last another week, a month, maybe even six months before they finally kill it. In the meantime, we can look for new devices that will support Hangouts if Obihai won't.