The latest design refresh of the Google Docs homepage added many useful features, but also made some controversial changes. Google decided to hide useful information like the last modified date and the list of collaborators from the list view because it was available in the sidebar.
If you missed the old interface, you can now switch to the details view and see some additional information next to the filename.
There's also a small icon that lets you temporarily hide the sidebar. For some reason, Google Docs doesn't permanently hide the sidebar when you click on the arrows.