I agree, it'd be sweet/realistic if a champions armor could get blood splattered over it just like their skin does.
However, I don't think it will make it into Ascension. The champions armor is unwrapped and textured in a different pattern than the champions bare skin is. Not only that, but armors that look completely different from each other will also be unwrapped/textured differently from each other. It'd be really hard to come up with a universal blood splatter pattern that wouldn't get stretched or distorted when textured onto the different armors.
They didn't get the blood working on the armor Kratos wore in the unlockable costumes in GoW III either.
This is a feature I would really like to see happen but I'm pretty sure we'll have to wait for a future game for it to be implemented.