Rich Swier of Startup Florida has a nice short article on Google+ and why he thinks it is a big improvement over Facebook. Google+ is still mostly a geek/early adopter phenomenon, but is probably the only competing service that has any chance of unseating Facebook.
Swier makes the point (and I agree) that a key advantage of Google+ is the ability to designate certain content only for certain folks in your network--the "circles" concept. You can create circles and put friends and family in them, and then when you post stuff, you can tag which circle or circles it is for. So instead of blasting everything to everyone (the Facebook approach), Google+ allows targeted posting and cuts down on the dreck.