Patch 3.0.2 (2008-10-14): Changed from increasing flight speed by 10% to reducing mana cost of shifting flight forms by 115.
The benefit from this item is reduced (!) if the druid has the Natural Shapeshifter talent.
Combined with the change to flight form (preventing a druid from switching to flight form while in combat), many consider this trinket of little worth. Night elves may still have some use for it when using the Shadowmeld ability to escape combat. Also, it lowers the threshold to escaping into Flight form between bouts of player vs player combat.