An improvement that I would like to see in WordPress is if an article (post) is published, the publish-date is marked as "today" and the article is brought forward in the theme and RSS feed as the latest. It doesn't matter if the article is created there and then (including articles created with a blog-editing program like Microsoft Live Writer) or has existed on the blog as a draft.
This is because you may put the article on the blog as a draft as a way of editing it across multiple computers for example. Then, when you publish the article using default settings, it doesn't appear at the "head" of your posts list or as the latest article on the RSS feed. I have to usually adjust the "publish date" to today in order to have the article at the "end of the RSS feed" and as the front-facing article.
Similarly, there could be the option to bring an already-published article that has had major revisions "up to the front" of the article list and RSS feed. This would certainly appeal to tech bloggers like myself who revise a post to bring it up to date with newer technology for example.
This could be achieved through "copying" the revised article up to a newer date or moving the article to a newer date and having support for a shortcut being held at the older article's position in the article list.
Another feature that could be of benefit to bloggers is to have a "sticky until" feature where they set a post to be "sticky" and at the front of the blog until a certain number of days/weeks/months have passed or until a certain date has been reached. The date could be set "in reference to" Eastern Hemisphere times or Western Hemisphere times to cater for articles that are to target North America for example.