Wave was over hyped, Buzz was under hyped.
Wave was not available to many, that made it useless. You were (luckily) in the wave, but then so what? Without many friends, what are you supposed to wave at?
Buzz was pushed as a free item. That took hit on its value. You were already in but the response was,"But ... but I was not ready for its hot-ness".
Google+ is pitched just in between. It has been properly hyped, being made available subsequently. Increasing the expectations and value. However, they have to rush the process of getting people in. I have a lot of friends who wanted in, but could not get in because of the systematic delay. They need to get in before it starts cooling like wave again. Google+ needs to catch the mood, and catch it fast.
The best thing so far, other than hangout, is that the wall posts are not automated.
I wonder how many people are already tired of automated $#!* they get on their facebook wall? If it was important to post, would not you already post it manually?