In the second (and last) part of the GWOnline.net interview with the GW1 Live Team, Robert Gee discusses upcoming changes to the Elementalist profession in Guild Wars 1:

GWOnline.net: Exhaustion – a few people call it the Ele’s exclusive stacking energy deep wound – is a mechanic that prevented the player to cast spells of certain power too often, when Prophecies came out almost seven years ago. At the current state of the game fast recharging, armor ignoring skills of other classes dominate damage dealing. How will exhaustion be changed in the update?

Robert Gee: As far as it functions as a balancing mechanic we actually like exhaustion a lot. Since it’s one of the only resources in the game that can’t be manipulated by other skills (with a few exceptions), its balance can remain mostly consistent. With that said however we felt that for many skills the exhaustion penalty did not accurately reflect the effectiveness of the skill. In order to address this problem, we’ve introduced exhaustion amounts of 5 in addition to the standard 10. We feel that this will make it less of a burden to take more exhaustion skills and will allow us to expand the number of viable exhaustion skills.
You can find the interview here.

See also this page on the wiki for a bit more info on these upcoming updates.