TES4 Oblivion was my first Elder Scrolls game so all zones of Cyrodill have a special spot in my memories.
My biggest hope is that ZOS does something with either Rosethorn Hall or Summitmist Manor as a player house. Back when the gold coast was made, the Anvil house from oblivion that had the lich in the basement was turned into the Anvil Bank much to my chagrin. As such Im hoping that ZOS allows us to have this easter egg.
Honestly the beauty of the Summitmist DB quest in Oblivion was that there was like a million different ways to tackle it depending on your playstyle. If ZOS really wants to do a throwback, they could try and do a similar quest with outcomes dependent not only on your choices but a player characters background, skills, and dialogue choices, similar to how there were different options for the Experiment with Peace quest in High Isle where there was a dialogue option if your PC had a high enough Alchemy skill or could just go all thieves guild style and just swipe the key to the storage room.
The only drawback i can think of is that it would require the VAs for the npc characters to do some more lines than usual.