If you have abandoned a project we urge you to please keep it on the site, but mark it as abandoned. This allows users to see the history of World of Warcraft interface development as well as for users who are new to the scene to see examples of what has been done in the past.
We will be manually marking some projects as abandoned that are obvious as being such, but for the most part it will be up to you, the authors, to do this.
The option is available within the main edit project page and when marked it will display a notice on your projects page about it being no longer in development. There is also now a search option for this and is enabled by default for any file searches.
This is becoming more important as 2.1 draws nearer, due to some AddOns not functioning properly in their current versions. Hopefully having your cancelled projects marked as so will help folks to avoid downloading it, which will save them time and frustration - something I'm sure we can all agree isn't fun to go through when looking for AddOns.