Well if people just don't want to play without fast travel, then why not make it as a kind of magic? So you could by teleport orbs/runes/trinkets at mages guild wich let you fast travel to a known location like oblivion fast travel. Of course the teleport stones would have to have a certain number for uses like enchanted items.
I like this. It's similar to my idea, but it's not "just another spell". Perhaps it could be something similar to Fable's method of travel? I could buy a stone, for say, 1000 gold? (Something you'll need to earn and can't use instantly), and it may only work for specific locations (Cities, settlements, landmarks, etc., pretty much important places). It always did annoy me that every random cave and ruin had a marker in Oblivion. I liked that most of the places in Morrowind where seemingly unimportant, and out of the way.
And about Divine Intervention being useless in Oblivion, thankfully, TESV probably won't be in Cyrodiil. I doubt the Imperial religion is widely accepted by other races (apart from the Bretons and Redguards who svck up to the empire
). If TESV is in Skyrim, I'd like to see something similar to Almsivi Intervention, for the local druid-like elemental religion. Using it, aswell as most of the unique elemental spells, would give a different effect to most spells. (Burst in a flame of fire, turn to dust and scatter in the wind, sink into the ground, just a few examples)