I do not have a Google+-shaped hole in my life right now. If a) it starts to matter to non-technical Internet users and b) they tie it into search heavily (which is the Google go-to playbook for promoting properties of strategic importance), I will start caring with alacrity.
Google+ will succeed because it's an exact clone of Facebook, but faster, more open to search engines (shocking!), integrated right into Gmail and makes it easier than Facebook to spam people.
The feature which Google is claiming to be the revolutionary new thing (Circles) has already existed in Facebook for a long time (lists and I've been using them). The problem with Facebook lists is that they are hidden, so most people don't know about them or can't be bothered to create them.
At first I thought Circles will fail like lists because it's too much work. But after playing with it for a few seconds, I realised Circles is going to be a huge win. Why? Because it's too much work and people LOVE wasting time on the internet. And it's fun dragging and dropping people into circles.
Whether you're a techie or not, you already know how to use Google+. Even if you want to avoid it, you won't be able to for long because it's going to be everywhere you go from now on.
Excuse the awful pun, but this thing's a vicious Circle.