Has there been any thoughts to how damage types will work? Or even if they'll be in CoT?

Will damage type be baked into a power and unchangeable? Or will it be adjustable like the graphical effects of the power? That is, will power X always have damage type Y, no matter what it looks like? Or, can will we be able to choose which damage type when we select the power.

Will defenses be typed like damage? Will a particular power always reduce the same types of damage, or will different players be able to select a different type?

And will powers have vulnerabilities? Something that temporarily debuffs the player? For example, a hit-point regeneration buff power that also debuffs resistance to fire at the same time. Or a huge area-of-effect nuke power that makes the user easier to hit for 4 seconds?

If there's flexibility in the design, it'll be much easier to make interesting powers.