When I read blogposts I normally read them in a reversed order. The latest post first and after that the second latest etc. When navigating between pages one has the alternatives "previous" and "next". Where "previous" leads to the page with posts with earlier publishing date than the the ones you currently are reading and "next" to posts with later (dates closer to present date). This is in my oppinion very confusing.
I'd like to se a navigation similar to the ajax advanced navigation but that display post per defined timeperiod. (eg. today, this week, june or 2007). So that I for example can choose from the navigation alternatives <may 2007 or juli 2007> when I'm reading the page that has all the june 2007 posts. This would mean that the static number of posts is replaced by a timeperiod defined number of posts. It would also affect the presentation of the navigation replacing next / previous but not name of next post/name of previous post.