I was looking for a solution in another forum but got no reply. I don't think this would be a terribly difficult to write plugin, but I for myself am not succeeding in doing so. Better said: I don't even know where to begin :)
This is the post: http://wordpress.org/support/topic/41808#post-234846
and the request is for a plugin that would make the blog start with the latest month that has posts instead of the last 5 - 10 posts. In this case the blog would start with all the posts in the latest month that actually has posts, being 20 posts or just one, but giving me in the same time the opportunity to add the months navigation right away.