WyldKard sent us this great piece he wrote over at mendax.org about building a better damage meter. DamageMeters is a pretty standard addon by this point, and considering that even Blizzard has started to include damage and healing figures in some battlegrounds now, players have generally agreed that tracking your healing or damage output is a fairly good way to determine your skill as a player.
Except that it really isn't. Wyld lays out a few reasons why, the most obvious being that one player outputting tons of damage doesn't mean your group actually succeeds. As a resto Shaman, I often get the short end of the stick on damage meters-- I do both healing and damage, so I never end up at the top of either list. Also, Earth Shield still isn't listed correctly even in the latest version of DamageMeters-- all of that healing, which I'm clearly responsible for, gets listed as the warrior's.
That's more of a bug fix, though (DM just has to get its numbers straight), and Wyld has bigger ideas in mind for damage meters.