Your Turn: XP Where XP is Due

So, I've been thinking about a solution to the "you only get XP for beatin' people up" problem. My idea is this. There should be a changable preference that pops up with each mission that lets you chose what your primary "role" will be in the mission. Options could be things like:
-Dealing damage.
-Taking damage.
-Healing.
-"Stealthing." (Resolving "glowie" missions with minimum kills.)
-Etc.

Each member of the team get's the option box pop-up when they join the mission. This rewards each hero for fulfilling their role in the mission. XP awards wouldn't come exclusively for their chosen role (a healer, for example, would still get some XP for defeating a foe) but a largest percentage of their total XP would come from the one chosen.

This doesn't fix the problem of Illusion controllers lack of XP for Deceived foes (which should definately be fixed as well), but it rewards Defenders for healing damage, invisible characters for stealthing, and tanks for taking the brunt of the damage.