WoW introduces achievement system?

Lord of the Rings Online has an achievement system, in which discovering things or killing a certain number of various sorts of mobs rewards you with titles or abilities. Warhammer Online announced they would have the "Tome of Knowledge", which also records your various achievements and gives some minor rewards for them. And now WoWInsider reports about rumors that World of Warcraft will introduce an achievement system in Wrath of the Lich King. Apparently you can get achievement points for example for exploration, for revealing the complete map of one continent. Or for things like completing a certain number of quests in one zone, or for doing 2,000 quests in total.

What I am a bit worried about is how such an achievement system is going to work with existing characters. Does it count if my level 70 characters already have revealed the whole map of Azeroth and Outlands, or already did 2,000 quests? How would I get the "reach level 15 without dying" achievement with a level 70 character, or a fresh level 55 deathknight? These sort of systems only work really well if introduced right from the start, grafting them into an existing game isn't quite that easy.

It isn't clear yet what sort of reward the WoW achievement system would hand out. The screenshots suggest some sort of point system, but what you can do with the points nobody knows yet. I'm hoping for things like titles, because I don't really see how you could hand out gear rewards which would be equally balanced for new and existing characters.

I'm not touching the whole "who steals features from whom" debate with a 10-foot pole. Fact is that that over the last 10 years MMORPGs have emerged as a proper genre of video games. That genre has a pool of features which are either expected, or optional. Every game grabs a lot of features from that pool, that is why they all belong to that same genre. And then sometimes one game adds new features to the pool, and if that feature works, it becomes part of the standard features of the genre. Who introduced which feature is only interesting to historians, and it isn't always the game that had the feature first which automatically has the best implementation of it. I'm looking forward to see WoW's implementation of the achievement system, because Blizzard tends to be good at improving features. I really don't mind if that isn't innovative.