I sincerely hope that Bethesda Softworks will embrace a co-op experience. Skyrim could have been so much more fun with two or three players sharing the same experience. It's not like this can't be done. One only has to point to Demon's Souls. The technology exists for this to happen in the next Elder Scrolls console campaign --(I'm not expressing wishes for the MMO).
If we are honest, the horse mechanics svck. Look at Red Dead Redemption to see how to properly incorporate horses. Not only that, at full gallop the console never chokes in RDR. Rockstar knows how to do something you don't.
Challenge is good. But, you gave enemy magic users way too much Magicka. A novice Necromancer could blast a similarly leveled player character with Flames while using a ward and never run out of Magicka. The standard encounter went something like this: Cast Oakflesh > Raise Dead or Summon Familiar > Cast Ward > Search for Player > Find Player > Maintain Ward and spam Frost, Flames or Shock. Meanwhile, the Player quickly depletes Magicka trying to do the same thing. Of course, the Player could chug potions. But that really cheapens the experience. For players like me, chugging potions is cheating and promotes careless play styles.
KILL CAMS -- NO MORE KILL CAMS!!!! If you have to have them, PLEASE give us a way to turn them off. Many of my stealth attacks with a bow have been ruined due to Kill Cam animations. They have got to go.
Quest Items -- Once a quest has been completed toggle the appropriate quest item flags. This will prevent players from winding up with items in inventory that can't be removed or sold. The Strange Amulet comes to mind if you need an example.
Give all versions of the game a Command Console to allow gamers finite control over --- well, bugs. If you are going to ship us buggy software and not allows us tools to remedy problems, then delay product until it is in a stable state.
GAME TESTING: Stop using your employees and relatives as Beta Testers. These people will never tell what is wrong with your game since they don't want to loose their job or hurt your feelings. Everything will always "be fine." Give the game to people who will do unexpected things. Don't give it to hard core games since they represent a small faction in the overall scheme. Hard core gamers will always want difficulty amped up and claim there are balance issues. New players will always find the game a tad complicated. It's the gamers that make up the middle ground that will provide the best feed back. They will keep the game from being too easy while making sure it isn't too complicated.
Hmmmmmm ....... I'm thinking...... I know there is a ton more to say.