I doubt it, personally. It is the main social meeja platform for Android devices. It's sort of the Android equivalent of Blackberry messaging.

Plus, most importantly, it's part of Google's profiling mechanism. They get to learn more about you when you fill in all the blurb about yourself (like people unwittingly do within Facebook), which helps target their revenue, and it's a good way of getting control over peoples photos. So, Google+ has a good 'garnering' purpose and costs virtually nothing to run in the larger Google scheme of things. In lots of ways it's the natural progression for the dying Google Groups, now that nobody uses email any more.

However, it's not really a Facebook rival, only the mainstream media make it out to be so, since they write everything as if it's all a big competition.

I think the main problem for people on Facebook and them trying out Google+ is that it's exactly the same as what would happen if one re-joined Facebook under a brand new name and somebody had zapped your memory of everybody else's names. You'd sign-up to Facebook and nothing would happen. You'd not know anybody, there'd be no conversations, nothing in your timeline, it would be very hard to build-up a 'friends' list, and you'd say Facebook was rubbish! People forget how hard and lonely Facebook was at the beginning, as well as how long it took them to build-up their friends lists.