I think Google+ is supposed to be a medium for sharing content, not for creating content. And while we've seen some blog-like posts there, sharing a link to your blog/tumblr/.. looks like a better option. Why? Because When you post it on google+, you don't have the many extras you can get in a dedicated blog. Especially the sharing buttons "tweet", "like", "digg", "stumble", etc. You only get a +1. In short - it takes a lot of control and a lot of options, and gives you nothing back.