Everybody knows that (like most web products) Google+ is an ongoing effort that is not complete. According to Google, it will be "several years" until the vision is really fulfilled.
Google's Vic Gundotra participated in a Hangout with Norwegian social media news channel Sosial direkte to talk about the "project" (he says they call it a project rather than a product because it's not complete).
"We had a couple hundred million active users...just in the stream...just on plus.google.com," he says. "And those numbers are numbers that we issued last year. That growth and that momentum has continued, and we're very excited about the progress we've made just in the last year and a few months."
Actually, here are the stats Gundotra shared in December: “Today Google+ is the fastest-growing network thingy ever. More than 500 million people have upgraded, 235 million are active across Google (+1′ing apps in Google Play, hanging out in Gmail, connecting with friends in Search…), and 135 million are active in just the stream,” he said.
The Vic Gundotra part starts about 34 minutes in.