I'd prefer them to give us a flat out potency increase. Don't need more movement skills, the ones we have in Triplecast and Between the Lines are rather decent. But we should be rewarded for standing still and casting by those high numbers.
Also I've said this a lot already, but if they wanna give us utility, I'd really like to see a Magic Resistance Down debuff, possibly tied to Umbral Hearts. I generally believe every class should be able to apply a debuff against their own type of dmg and not have to rely on others to put it up for them.