User blog comment:Sarah Manley/Sneak Peek at the New Look - Community Activity/@comment-1272587-20100827013028/@comment-1613840-20100827171232

Seahorseruler, The timestamp on the history dropdown will behave similarly to the activity feed in that if it has been a while since the last edit, the timestamp will no longer be visible. This is done, just as you mentioned, so that a new visitor to that page is not discouraged from editing on an inactive wiki.