Still, the value of avoiding a Buzz-like privacy fiasco is well worth the risk of letting Facebook and others respond to Google+ before it's widely available, according to Forrester Research analyst Josh Bernoff.

"Facebook is indeed in a position to replicate the best of what it sees out there. You see this happening all the time -- LinkedIn copies Facebook, Facebook copies Twitter, Google copies Facebook, ad infinitum," Bernoff said. "But Facebook is what it is, and that's horrendously complicated [in its privacy controls]. It's not easy to fix that by copying something Google invented that's simple."

Google deserves credit for assuming that competitive risk and also for resisting the calls to open up the service widely more quickly, Bernoff said. "This strategy is better than flinging it out to everyone when it's not fully cooked. In fact, I think they have it about right, but the pressure to make this completely open will be very significant given the attention it's getting," he said.