[simonw]

I like using years for namespaces because I like thinking long-term - in 50 years time, will that site's namespace be getting too busy? Using years means you can even completely change the rest of your URL scheme without needing to update last year's URLs.

Quickly letting users use the age of the article is a good reason too, but only for blog-style content. I don't think you should use the year trick with evergreen content (example.com/2010/terms-of-service for example).

[eru]

example.com/2010/terms-of-service would still be a good URL for the namespace reforming reasons you cited.