This. What better "class" to summon forth a blizzard than a Druid/Shaman type character. Don't have to make a new school for nature magic either. Damage nature spells would fit in Destruction, A vines/earth spell that immobilized would go under alteration. Various summons, as mentioned already, like Spriggans would go under Conjuration.
In the end, I don't know if I really care if they added it. I don't feel like I need the magic system to be like D&D or other traditional "fantasy" games. And there is enough to RP a Druid already with imagination.
One of the problems with that, however, is that the way the skill/perk system is currently arranged, you'd have to crawl through all of the various perk trees and buff several skills only to get one or two "useful" (RP-wise) spells/perks from each. That'd be tough to do under the current system ... I'd think. Thus the argument for a seperate school -- i.e., skill.
I've never been one to use a lot of, nor rely on, destruction spells, so I have a hard time commenting on that school in general. But like many, and involving a school I did use a lot in Oblivion, I'm disappointed in the small variety of summons spells. I think the missed an opportunity to create a seperate school for necromancy so that both it and conjuration could remain relatively robust with variety.