In order to refrain from possible duplicate URLs or conflicting URLs, I really want to use "postname" for a clean URL structure, EXCEPT for the blog ... for the blog and it's posts, I always want /blog/ to be apart of the URL. This makes total sense, and I don't quite understand why it doesn't function like this when you specifically select a Page to represent the blog.
http://www.mydomain.com/this-is-a-page/
http://www.mydomain.com/blog/
http://www.mydomain.com/blog/my-blog-post/