If you have blog, like the WordPress Development Blog, where you have multiple authors, then you might want to take a look at the Post Moderation Plugin

Post Moderation is a plugin for Wordpress, allowing multiple authors on your site while still maintaining editorial controls.

Features

• Moderated Author Level
  Posts from authors at or below this level will be set aside for approval.
• Moderator Level
  Authors at or above this level can approve queued posts for publishing.
• Notification
  Uses a javascript popup to notify a moderated author that their post has been queued for approval. A slight improvement to the way comments are handled until there is some form of error reporting system.
• Database Modifications
  Uses minor database modifications that can be installed by the plugin or added manually with SQL generated by the script that can be copy-pasted.
• Deactivated Plugin Options
  If the plugin is deactivated while there are posts waiting for approval, posts can be sent to draft/private/publish or be deleted.

It would be nice it it had the additional feature of the administrator or moderators being informed through email whenever a new draft is posted to the blog.