Iit’s totally clear that Google+ Photos service will become an independent service very soon. So while losing it’s most anticipated and praised feature, Google+ should become what Google always claimed it isn’t: simply a social network.
Thanks to Android, hundred millions of users all over the world already have Google+ pre-installed, and Google should finally take real use of this. Currently, if someone opens the Google+ app - maybe per accident or because of curiosity - he is halted by a characterless screen-filling sign in page. Google+ already has a bad reputation because of all this login stuff, and for a new user this login screen might just be a verification and the reason to leave the app again.
Instead, Google+ could act more like YouTube, giving the user the possibility to discover it’s advantages and greatness without the direct need to sign up first. Of course Google+ and YouTube are very different services, but the concept could certainly be applied anyway. While this might not work for most social networks, Google+ is a very underestimated service, with an overwhelming user experience, that could be capable to convince users to voluntarily sign up permanently after testing it for a while.