Along with the fire spells and they can interact with the environment and with NPCs, how do you think Frost/Ice will react to the environment? Because there is a new spell called Ice Spike. How do you NPCs will react to it? Thoughts? Opinions?

I think that's confirmed that ice spell will leave a mark on skin and slowsdown npc.

I think they'll react by having an icicle driven through their body. See how they go after that!

I wonder if "Ice Spike" will damage Nords, due to their frost resistance.

Long, I have been thinking of doing just lightning and Fire... but this "Spike" attack sounds physical.

I mean if you think about it if someone drove a ice spike into someone it would probably kill them, but it also depends on where you impale them with it.

I'm looking to see the "limb" system in Fallout 3 totally revamped...

I want to be able to cripple an enemies testicles. lol

The limb system from Fallout 3 is a staple of the series, it has nothing to do with TES as of yet.
I do however suspect that Skyrim will feature localised damage, but that is pure speculation.

If there are effects like slow attached to a frost spell I wonder if something like resistance to frost damage will also (at least partially) nullify the slow effect

Roll armour and magic resistance.... death or a minor flesh wound