Realism
Snow falls realistic with the wind (posibly gathers on the ground)
tree branches now have weight added to them and will move with the wind and you
water flows with the wind and downstream
you can now see much further
Character
10 races (presumbly same as morrowind and oblivion)
there are now 18 skills instead of 21
perks are added and there is over 180 of them
there is no longer a HUD
there is level scaling but it has changed (example i walk into a cave and all enimies are scaled but they stay that level forever)
agility, endurance, intelligence, personality, stength, willpower and luck have been removed and replaced with heath, fatigue and magicka
smithing and enchating skills have been added
better character creation you can now change body size or add beards and more
Travel
Athlectics and acrobatics have been removed
you now move backwards much more slowly
there is fast travel
there is sprint
magic
mysticism has been removed
you must have a free hand to cast spells
you can alocate two spells to each hand to create a stronger versions (mixing spells may be possible)
dragon shouts are gained by learning there language to construct sentences
once you kill a dragon you can adsorb their soul but what they do is currently unknown
combat
you can now allocate a spell or weapon to each hand
finishing moves have been added
bows will be slower but more powerfull
new combat mechanics
World
there is 5 major citys (surrounded by walls)
farming, cooking, woodcutting, blacksmithing and mining are available as jobs
the dungeons caves etc are now designed by a team of8 instead of one person
Quests
randomly generated quests that searchs for caves and dungeons that you havent been to yet and adds stuff
Interaction
when you enter chat it longers frezes time
if you drop a sword in town someone might pick it up and give it to you or a fight might break out between men over who gets it or if the nps hates you enogh he'll pick it up and use it to attack you
there will be kids