I like the idea of having a single place for players to go to see if there are any planned matches coming up. On Steam our "Official Group" serves this purpose because we can create an "Event" which all members of the group can see and add comments to. The time of the event is displayed in the viewers local timezone and there is an IM sent when the event starts. Old events vanish from the page.
A single forum thread would work kind of like this, but is harder to quickly read and selectively "join" an event. I would like to see something closer to the Steam approach, simple and clean, but tailored to Clones. A single "events" page with Drupal nodes created by users indicating when they will have a server up, and the nodes will auto-delete (or archive) a few hours after the start time of the event. Similar to the Level gallery listings. Players can comment to indicate they will be joining the server and comments can trigger emails to the node creator. Any other thoughts to improve this concept?