I was pretty excited when Google+ started rolling out. And as I've looked at the features, it seems to have all of the things that we love about delicio.us, skype, Facebook and e-mail rolled into one. The thing is that we are already using those other platforms. And unless Google+ becomes ubiquitous, then it won't be useful. So, why would someone make the jump?
The one thing that Google+ seems to do better than any of the other platforms is create separation of your circles of friends. In Facebook--while you may be able to group friends--the groups are simply labels. They create a way for you to find different categories of people quickly. But in Google, the separations work more like they do in real life. The only people who see each other are the circles you've created.
So, given that most of us aren't fans of double lives...why does this even matter? Let's say that you teach a middle school class at church and your students have friended you on Facebook. You love sending them messages and they message you too. And let's say that you are also working with a ministry that is active in speaking out against human trafficking--and some of the images, stories and comments posted aren't exactly PG-13 because human trafficking isn't "safe for the whole family." In real life, there would be no crossover between these two groups of people, but online there is. If you comment on something or are tagged in a photo, it is visible to your whole group of friends. (Unless you have really complex privacy settings which are possible but not likely.) All of a sudden, you become a conduit for imagery and information--whether you intend to or not.
Separation of circles also helps keep things in context. You can be completely transparent with your friend circle if there is a personal crisis without creating instability your professional one. Google's circle approach allows you to share the appropriate information with the appropriate level of relationship while still having access to all of the functionality of a social media platform.
For a tour of all of the cool features of Google+, check out The Google+ Project.