One thing that bugs me a little, is that whilst one may only want one blog post to show up per page (especially true for blogs with longer posts) the search and filter by tag function should have a separate limit.
The way it currently works is that if you have it set on 1 post maximum per page, when some-one searches or clicks a tag, they can only get one result per page, so they otherwise have to trawl through the 'previous pages' link, or in many cases give up and think that that's the end of the search.
I think that it'd be good if under the "Reading Settings" there was a setting for "Blog pages show at most X posts" and "Search and Tag pages show at most X posts".
On a side note as well, it'd be great if the search function also searched the tags as well as the body text. It would make it more accurate.