I'll start:
I'd bet a million septims Skyrim has:
A Vats type feature (maybe for finishing moves or magic)
A romance option
Companions with they're own side quests
Dual Wielding weapons
Prettier faces
Better animations
Locations that aren't covered in snow
An invasion from akavir as the main plot
You will be the dragon born
Werewolfs and vampires
Falmer ruins kinda like the aylieds
The plot heavily involves tiber septim
I'd bet Skyrim doesn't have
Dismemberment
Best races with Morrowind style animation
Your character starting in jail (betting they're going to change it up)
A survival game mode (like new vegas)