I made a definitive list of things this game does better than Morrowind and things Morrowind does better than this game. Yours may vary.
How Oblivion is superior to Morrowind
-Graphics that actually make you want to look at them
-Better-scripted quests and freelance quests
-Better main story
-Far more stable
-Better sound design (music and effects)
-Combat that's actually fun and not tedious
-Improved lockpicking
-Improved interface/menus
-Far fewer fetch quests, though they are still present
-Fast travel system if you are so inclined
-Poisons
-Radiant AI/character interactions
-Physics
-Horses
-More immediate payoff for home-buying system
-NPC's aren't merely clones, each has a specific role in society
-Much more difficult to break the game's stat system in your favor
-Forts, ruins, and caves have far better designs, complete with booby traps, underground lakes, and other things.
-NPC's can now enter doors both for combat and routine purposes
Things Morrowind does better than this game
-Sneaking into buildings/homes and stealing things is completely taken away by the game's item scaling system, which for some reason has no effect on towns. You can also find illogical bumps in the gear/weapons your adversaries are carrying, as glass, ebony, and daedric armor eventually becomes commonplace.
-Level scaling for enemies may irk people, as it punishes the player for leveling quickly
-Faction system is really dumbed down, no great houses or vampire clans for instance
-Need to complete several quests just to make spells/enchantments, Morrowind had fewer I think.
-More weapon types
-This may be a minus or a plus, but the merchant system is less realistic now because of the unlimited funds.
I think the end result of what has changed with Oblivion is that you feel less inclined to make dangerous journeys, and more inclined to take calculated risks, marvel at your surroundings, and complete freelance quests.
My verdict at this stage (35 hours in) is that Betheda designed a great game which has far less to do with the stat system they developed for Morrowind.