Blog Engines Need to Be More Complex

Movable Type is starting to bug me. I don’t have a consistent blogging pattern, some days I blog 5 times, sometimes i wait 2 weeks between posts, and I have to pick between a number of posts to leave on the main page (usually 5) or a number of days to leave up (usually 10), there is no way to do something more elaborate.
I would like to be able to have there to always be at least 5 entries on the main page, regardless of age, but if I have blogged 25 entries in the past 10 days, I want them to all be there.