The good folks over at GuildWars2Hub.com have the first part of a two part interview up with Jon Peters discussing professions and traits. There is a lot of focus in this first part on the trait changes that we saw in BWE2 with the implementation of the trait tiers, to which Jon responded:
Anytime you change something that you have already shown, there will be people who liked what they had and resist that change. This is just a universal truth. There is also currently a misconception that Guild Wars 2 lacks character customization compared to the original Guild Wars. This is expected as we intentionally reduced the number of options for each choice in order to make each system easier to understand; however, we countered this by creating more choices and more interaction between those choices.
He also spent a good bit of time discussing the Engineer and revealed an interesting change to the mine kit:
Mine Kit is no longer a kit. It is a single mine that works as the elements of the kit did, but now, when you detonate that mine, it knocks enemies back and removes boons. This means that you can throw it at your feet and then blast people away from you, or you can throw it past a fleeing enemy and detonate it to blast them back toward you. The tool belt has been replaced with a “drop mine field around my location” skill, which toggles to “detonate mine field.”