The theme of GW2 is camaraderie, so why not add a fun mechanic to the current death system? When a player reaches reaches 0 HP AND is defeated in the "down status", you have 2 options
1. Try to rez them like normal (and die an epic death from the enemy's AOE attacks)
or you can
2. Scoop them up in your arms (or help them up shoulder to shoulder Bromance style) complete with fancy heart warming animations and all.
Obvious benefit of this, besides pleasing aesthetic reasons, is that you are pulling them to a safe place where you and/or other people can rez them. You can still fight while carrying them (but they cannot) but your stats would be halved.
Also, what about a Grab mechanic? At exactly 0:23 in the following video, best describes what I mean:
No? There's no super genius who has figured out how to code 50 bazillion people trying to cling onto a giant monster in an MMO setting yet?...