Display types of posts in edit.php instead of All, Published, Scheduled and Draft

Why don’t you just take post_formats (will be introduced with wp 3.1 in near future). These contain asides (small posts), chat, links, video, audio and so on. In general you just got a new meta-box that allows you to select the format when posting. Behind the scenes post formats are just predefined custom taxonomies bundled in a meta box. I don’t know how they list, but i guess it’s close to what you’re searching for. Else you could switch to custom post types. Those would be listed as separate menu entries, so when you’re on the post-list screen you’d only see the type of post you want to see. You could make custom capabilities that are only added to specific authors so only them could see their “own” post type. Hope that helps.