I think google+ will not grow all that much.
They now place all reliance on getting the REAL names of users.
As google said, REAL NAMES are what advertisers want!
So they want your real name so that THEY can make money off it.
For google, it is all about controlling your online presence and making money from that presence.
I for one, will bypass google+ because I am not going to give them my REAL name, address, phone number, etc.