Arena.Net's John Peters has written an extensive look at the Attribute and Traits that will ship with Guild Wars 2. The blog post goes into great detail about the differences between the two and why the dev team feels like traits aren't just a grand theoretical idea but are a way to make a player's character their own.
As a player, the new trait system has made me think harder when building a character and has made me really excited every time I hit a level over 11.
For the first time, traits don’t feel like just a great theoretical idea. They feel like the system they were meant to be—one that makes my warrior mine. Do I put 30 points in Defense, 30 in Tactics, and 10 in Discipline, to maximize survivability and major traits? Maybe a less traditional build with 26 points in Strength, 26 in Mastery, and 18 in Discipline would work better for my play style. The choices are actually staggering at times, but don’t worry, you’ll have hundreds of hours to turn the knobs to your heart’s content.
Treat yourself to a great Tuesday read on the Guild Wars 2 site.