Zuck said unnamed new apps possibly won't require you to log-in and this is a giant step forward for identity? Wait until they actually do it and then wait until they do it with something important.
I wrote up some thoughts on Snapchat's mainstreaming of anonymity/ephemerality a few months ago -- and believe there are huge opportunities out there for people who will go where Facebook/Google won't: http://chrishateswriting.com/post/67378144174/ephemerality-g...
A single, merged, adult-centric identity visible to parents/mentors/distant-acquaintances/professional-colleagues is especially unattractive to this key demographic.