Have you not been paying any attention to what Beth's been doing with Fallout 3? It might be poor by Fallout standards, but by TES standards it looks to be Beth's best game yet. I'd love to see them bring some of the stuff they're doing in Fallout 3 to TES V. It's like what Oblivion should have been (i.e. an improvement on Morrowind).
EDIT: Just to clarify, I'm not talking lore here; I'm talking gameplay. ('Fallout 3 without guns' being as it is a reference to 'Oblivion with guns', which is to do with the gameplay styles, not bringing elves and wizards to Fallout)
Though a lot of people seem to be moaning about magic swingin' zombies roaming the wasteland.
Anyway - you're right from the gameplay perspective. And from the lore side of view, based on how they butchered the Fallout lore.. well, it's not like they didn't allready do it to TES with Oblivion.
Can only get better from here.
An adventure game set in a city that is beautifully detailed is much better than a huge provence with copy paste dungeon lay out and generic archetecture etc (Oblivion). As far as gameplay and fun go a city is better than a provence. An adventure game would alow for better dialogue and better story telling over a streight out rpg. An adventure game would not be limited to hack and slash at all. Games I've played whose apropriate elements together in TES context would be awesome: Thief, Wind Waker, God of War, and Redguard are good templates. It'll never happen, what a shame.
Oh and scale wouldn't need to be sacrificed so much.
Adventure games? Having better dialogue?
Now, of the games you brought up, I've only played Thief (Thief II, to be precise, but I'm hoping they're alike), and sure, it was an awesome game. But the dialogue was... Well, to begin with, it was completely stream lined. So was the game.
Dialogue is definitly best in the hands of RPGs, where you can choose what to say. You know, the whole choice and consequence stuff. That TES often lacks.
Come to think of it, TES as a whole lies almost closer to "adventure/action" than to RPG. Especially Oblivion.