For one thing, spells will have greater depth to them, with three portions named thus far by bethesda (at least as far as fire, ice, and lightning goes)
-Instant (ex: quick fireball)
-Hold down cast button (ex: flamethrower)
-Rune on ground, like a magical trap.
Wow. With some coding, holding down the cast button on a new custom spell could charge a force push, or you could make a spell that incribes a glyph on the ground that sends enemies flying skywards, to crash down on the ground (think Sheogorath's answer to you attacking him ). With these new options, the possiblilities look much extended.
So, the poll above asks your opinion of the new modding engine, and what kind of mod you plan to make first. Also, post below if you want to share a specific mod idea you'd like to implement, or that you'd like to see a modder implement.
I'll go first, I'd love to make a Bleach Mod that has abilities like Cero and Flash Step. Cero would have been very difficult to implement well in Oblivion, but in Skyrim it looks relatively simple to make it a "hold down cast button" type effect to charge it.
Aside from that, a zombie infection (or werewolf infection) little mod is a must