I've been involved with a number of turndowns, Buzz (1st time, and then the double-tap project). Orkut, Hangouts on Air, Google+ Stories, +1s on the web and more. As stewards of user data I would like to propose that we do something different this time.
While we can't keep the service active we can at least do something useful with the output and give back agency to the users that created the data. So here's my proposal.
1) Create the Plus Cooperative(*), owned by the users of Google+. Each post you made prior to a cutoff date gets you one share in the new entity. Decisions are one-user, one-vote.
2) Transfer the plus.google.com domain over to this new entity or redirect to a new plus.coop domain. Generate a static dump of the public** contents and transfer that to new infrastructure run by the Plus Cooperative. In addition Google provides a full dump to the Internet Archive.
3) Google funds the organization for at minimum 10 years off a one time grant.
4) Google publishes a set of identifiers/claims that would allow a user to gain access to the public data in question. The user could choose to remove data from the plus.coop domain or add their own redirect (a super idea suggested by +104122652599862501408)
5) The Plus Coop would be governed by it's user-owners and could choose how to invest in their infrastructure/product. They could create migration tools, publishing tools -- they could even revive the service starting with the seed data.
To me this is full-on "Respect the Opportunity". There are enough passionate users out there to keep the spark of G+ going; let's not get in their way.
And let's not 404 8 years of cultural history.
* There was an attempt to transform twitter into a Co-op, so this idea is not really my own.
** We could conceivably export private data if it was suitably encrypted and a user could claim it at a later point. But that's very much a stretch goal.
*** I also think that all products should buy Bonds that would fund a similar data preservation effort upon failure/cancellation.
cc: +110664632946820915121 / +115753604102260948135 / +101587921131889992978 / +110940801340246898787 / +115283013747081617765