Honestly. The fact that people haven't quite grasped that social media is all about fads is a little scary to me. You don't really have to a deliver a 'product' as anything other than a slick UI that allows people to play with each other. It's communication for entertainment's sake.
There is no point to using social media other than event invites, relationship status and pictures. That's the only useful features. Well, and contact information, but you've already got their contact info if they're really your friend.
I know, I know. You're going to defend your meek social interaction through comments and statuses and links and videos and all kinds of other nonsense. We've had forums for years. Some people make friends on forums but they're going to stick to the forums, not their facebook.
Google+ is just the latest reincarnation of the social media supersite. After them will be another. It doesn't matter to anyone what site they use as long as it's new and it's slicker. Why do they not care? Because there's no value in it besides the 3 things I mentioned above. As long as everyone they know is on the site, they'll use it.
So what's the killer product nobody's made yet? Quite simply it's a service that integrates every communication medium that people use. If (for example) you had a deal with every major wireless carrier to carry your apps and optimized communication through each varying protocol (SMS, SMTP, voice, HTTP, etc) to allow seamless and instant communication, there'd be no reason not to use it. If nobody ever had to sign up to a service because they were instantly and intrinsically enjoined with it there'd be nothing much else to sway one's opinion (besides Farmville). Nor would you have a choice, really.
And that's not to put down Farmville: Mindless games and apps have huge value for their market, but you don't need a social media network for that. Moreover, this seamless communication medium would allow you a framework to build apps which could reach anyone anywhere. Combine the dedicated carrier apps with a means to ship targeted "value-adding" applications and you've got one powerful, flexible social engine.
The way I see it is, all of these "sites" are based on some archaic notion that people should be using "the web" to get what it is they want. I disagree. I see every device with a network stack as simply a means to an end. The ends are basic: communication, information/entertainment and acquiring of goods/services. You can do all of those things with SMTP and POP3 if the sent and received messages are tailored for the application.
So let's unburden ourselves from the chains of some complex and limiting set of protocols and scripting languages. Nobody *needs* an app or a site. What we need are practical multifaceted interfaces to basic human interaction.
Google+ isn't going to give us that. The next site that replaces Google+ when the hoedown continues and the winds change, also won't give us that. But maybe once we've wasted enough time playing with our toys we'll finally get tired enough to just make tools that give us what we need and not always what we think we want.