Skyrim - A Closer Look @ IGN

This isn't as informative as the title sounds.  IGN compares the handful of released Skyrim screens to Oblivion but it's entirely speculative:

Hitting someone with a fireball in Oblivion was a satisfying act. It dealt damage, made you feel like a badass, and sometimes caused the targets to fly across the landscape like victims of fatal trampoline accidents. In Skyrim, judging by this screenshot and the small flecks of flame around the impact point, it looks as though the spell effects will be much more detailed. Bethesda decided to reduce the total schools of magic from Oblivion, dropping Mysticism, but that doesn't mean there'll be less to choose from in terms of combat options. Leveling will be faster and Skyrim will include Fallout-like perks.