If GW was to implement it, then retaining the creative combinations of spells from Pathfinder would be one of my favorite features. I have a lot of mmories of combinations used in innovative or funny ways, like a puddle of water being summoned under a door and then elctrified to kill the person behind it or using stone to mud and then mud to stone to trap enemies or negate the effects of wind or gravity manipulation or using a voice activated Delayed Fireball combined with Magic Mouth to set up a trap to name just a few.