As much as it sounds wonderful and a good alternative to Facebook, I don't see Google+ being used among the common denominator of people who are still stuck on Facebook and aren't too quick to want to try something else out unless they're unhappy with what they're using already. It's similar to how people were stuck on Myspace for the longest time before transferring to Facebook because they realized that having neon colors, glittery photos, and obnoxious music auto-playing every time they visited a friend's profile wasn't too enjoyable. If Google+ really is the next shit, I'd still give it a while for people to stop asking "What's Google+?".
If it does take off well, I will probably grow sick of hearing people say "Hey, let me add you as a friend on my +" and "Tee hee, your photos on + are soooooo cute!".