this thread is completley off topic..
google+ (aka G+) IS in fact a Social Network. It's meant for you to join, and SHARE with other member's.. IF you have a Google Account (Gmail, GDocs, YouTube, etc) you have a Google+ Account.. It's esentially the backbone of Google's services now. It holds everything you've done on the web while logged in, It is how Google Identifies you.
Log into ANY google Service, look at the top bar and it'll say +yourname (mine says +Raymond) - this links to your G+ page.. Yes you can "Opt Out" of it, so to speak.
With Hangouts, its essentially iMessage/Facebook Messenger/Skype/BBM.. Which are ALL essentially part of a Social Network of sorts.
I, for one, am eXTREAMLY excited for this, I love the G+ app, and the fact all my pictures get auto-uploaded, as well as having a unified service. I guess I trust Google a bit more then other's do. I have nothing to hide what so ever, and I dont need SUPER HI-RES PICTURES/VIDEOS uploaded.. I have a $600 SLR that's dedicated to taking pictures, its great for WEB QUALITY SHOTS and for sharing with my friends through Hangouts/MMS/FB Messenger (nobody i know uses Skype-it sucks)
Having it integrated is AWESOME though, less confusion, and i've already gotten soo many on board, and if it operates like iMessage in any way or shape, it'll be the greatest thing to come to Android! and it'd complete the Google Messenger Experience we've all been looking for (Before hangouts, and when GTalk/Messenger/GVoice were around)