I don't think the news feed/wall is a place for vanity. It really depends on the user. Your example of the guy trying to look smart+cutting edge makes sense. For me though, I like to keep my Facebook free of tech/coding stuff even though that is a large part of my life. It has no relevance to my Facebook friends so it should not be there. I put that type of stuff on twitter, and on twitter I do not follow people who I am Facebook friends with (and do not allow them to follow me).

In other words my entire online life is compartmentalized. It makes sense for me to do this even though it can be tedious. Circles would make this a lot easier by the looks of things, giving me one place to post everything, simply choosing who sees what content.

Getting people to use Google+ when they already use Facebook and/or Twitter though is Google's biggest challenge.