I'm sure it will be useful for some people but I'm pretty skeptical of all this "social " stuff. Most of my online communication is compartmentalized and direct and I like it that way. As a result it's hard for me to judge it since I'm looking at the product from the "will I* use this? Is it useful to ME?" perspective. The one thing I'm pretty confident about is the UI looks overly complex and convoluted for the average person to use. (look at the success of Twitter and Facebook UI change uproar for proof of that) I think Google needs to seriously improve the UI if they want it to be a mainstream product. Otherwise I see it being a niche service for people who really need this type of tool.