It's been 22 months since Beau Lebens' inspiring WCSF'13 vaporware talk where he promised O2 in beta in "about a month." The O2 team may be officially off project now, but my guess is they haven't been on it much in the past 22 months. My guess is that somewhere along the way Automattic decided they liked Slack better than O2 and this dump onto GitHub is the finally announced postmortem. Still, Slack, while awesome, is proprietary and not publicly viewable, so the possibility that someone may fork O2 from GitHub is still inspiring.