The only notable exception is "Hangouts," the feature that lets you host group video chats with your friends. It's pretty cool, but again, I can't see someone ditching Facebook just so they can video chat.
Yes, it will help that Google+ is baked into Google services like Gmail, but that still doesn't mean all those users will suddenly stop using Facebook because there's now a "+You" button at the top of their inboxes.
Everyone's already on Facebook, and most don't use Gmail. A social network is no good unless your friends are on it too.
As my colleague Dan Frommer put it: "It's like Facebook with no people".