I'd rather they didn't split up combat and utility. Partly because it can be hard to define what's utility--it's not hard to define combat, because anything can have a combat use given creativity and preparation, but most of the time people try to force noncombat stuff by making it take too long or some other arbitrary distinction, and that takes the fun out of using noncombat stuff in combat. Partly because having them both in the same slots means you can build an entirely-utility character just as much as an entirely-combat character, and that's the kind of caster that tends to get neglected. Partly because I honestly don't trust WotC to do utility magic well; look at how 4e rituals turned out. And partly because the main reason to use Vancian magic at all is to encourage preparation and planning, and deciding how to divvy up combat and utility slots is part of that.