As to the DPS meters, Arenanet definitely wouldn't implement them for themselves, but I think people will find the way to create something of sort. When I played Rift and the devs didn't allow players to customise the UI for the most part, moders created some kind of 3 party program, which ran alongside with the game, and collected the data. So, we will see on that one.
Meter and even Gear Comparison are good features to have, in of themselves, but the way people react to them is generally flawed. Both are simply information gathering tools, but people with superiority/inferiority complexes usually corrupt the meaning.
In WoW, I've always had Dmg Meters, it was one of the first mods I ever installed, as it was the only way to guage MY OWN performance, and as long as whatever group or raid I was in was progressing through content, I didn't care if others were under performing, I was trying to "beat my own records" or catch up to the people who were performing better than me. But there have always been the arseholes that simply because they do X amount dmg, they believe it gives them the right to slander everyone who does less. GearScore made things even worse. Which mostly in fault of the players who chose to be ignorant to the literal/effective workings of the game.
With WoW being designed around Gear>Skill, if you had two people in equal gear and equal skill, they'd do exactly the same dmg. But if you modify the Gear to Skill ratio between the two (in this case, Better gear on the Less Skilled player) it eventually reaches a point where no matter how skilled you are, you're not going to out-dps the hurp-a-durp faceroller that has better epics. Oh how many times, I'd go to a PUG Raid, and the organizer refused to take one of my friends because they're GearScore was slightly too low, and we'd lay into the bosses, and the dps in the best gear was doing 1/2 the dmg as everyone else, but that was just fine and dandy, cause hey, he had the highest GearScore, right? Anyway, the problem is not the meters, it's the players misusing them as tools.
I'm getting more and more excited about GW2 having less focus on "Endgame", because the definition of the term in Gaming Standards these days is more like "The End of the Game"...