"You might find yourself finishing the dungeon naked or on gear drops that you happened to find as loot to replaced your own broken pieces"
Found this on a massively article. Apparently you can break all your armor and be unable to repair it in the field. I guess the equivalent of DPing out.
"Explorable mode, particularly, still needs some loving attention before that sort of thing will be true for all the encounters (I'm looking at you, boss-with-undodgeable-pull-of-instant-death),"
Edit: I've been looking over a lot of GW2 videos, and there is a pretty common theme of mentioning that the dungeons need tweaked, from both reviewers and even devs saying they're absurdly hard. I think it's a safe bet the instagibs will be toned down.