Two things which I would like to see in wordpress
1. Separate user interface for the standard user which integrates itself within the theme. i.e. Standard users should not get to the admin area altogether. It would be great if people register, login and are presented with the web site pages as per normal with ability to add a post and manage their profile only (much like this forum operates).
My reason for suggesting this purely comes to down to not wanting people accessing the admin area if they are not an administrator.
2. It would be nice to have a built in post view / ratings functionality. The hits would be easier to implement I guess. Then you could see the view counter in the admin -> edit posts as a separate column.
Just thinking might I add another thing - a forum capability. Some ability to treat a particular category as a forum (I know bbpress exists but integrating that with wordpress is not a simple task even if its all automated, the theme portion is not simple).