- More spell variety, more crazy combos to make
- A Mage's quest line where you lobby to bring back Levitation, Jump, Slow Fall, etc
- Mark/Recall, Interventions, Morrowind style fast travel where you have to think about how you manage you time
- More varied art design so each city actually looks and feels different -> See Morrowind
Anvil got this right, pretty much every other city got it wrong. Different architectural design, sure, but always the same colour palette
- Lore-based critters. Less generic fantasy beasties. In other words, more Guar, less deer
- I WANT MY RANGED WEAPONS BACK. We bitched about this on the forums when Oblivion was announced and I haven't gotten over it!
- More guilds, longer guild quest-lines. Re-create sense of rivalry that permeated Morrowind
- More random 'stumble-upon' side quests, but FO3 had plenty of these so I think they are getting better
- And finally, if they have time, new animations and game system. Non-essential, but would be nice.