I'm cautiously interested, but Oblivion's main draw was the insane quantity of mods available. Places, quests, items, game mechanic improvements (if you only install one mod, make it KCAS to fix the awful default levelling system) all sorts of stuff. And I don't expect that most of those mods will be converted to the remaster simply because the people who made them will have moved on.
I'll still pick the game up when it comes out, but I don't know if I'll enjoy it as much as the original. At least half of my Oblivion playtime was added by mods. More like 2/3, perhaps even 75%.
As for comparing Oblivion with other TES games, I'd still rank it as the best. Now, I've never actually played Morrowind or Skyrim. I've only seen Let's Plays of them.
Morrowind? Yes, it's perhaps a little mechanically deeper, but the world is much smaller with less detail and it's got some extremely annoying game mechanics (spell fizzling, weapon strikes flat out missing for no obvious reason). People ragged on Oblivion's repetitive voice acting, but it added real depth to the world. Depth that Morrowind lacks. And as others have mentioned, the world is quite bland and colourless.
Skyrim the game has a nicer engine - more detail, nicer effects, better performance. The game mechanics were changed and I'm ambivalent on whether that's good or not (you can no longer get 100% magic immunity). But Skyrim the place has the same flaw as Morrowind the place - it's an icy frozen wasteland. Grey, white, brown and tiny little bits of green here and there.
Fallout 3? Not a TES game, but it's also a dead colourless wasteland (though there's a very good reason for that).
Fallout New Vegas? It had more colour, but being a desert, it's a desolate inhospitable hellhole by default.
But Oblivion's world is a lush verdant paradise. Not so much up north, where it's cold and snowy - but that's fine. It's got actual biomes and real contrast between them. If it weren't for the demonic invasions, caves full of goblins, bandit gangs, monster attacks and all sorts of other fantasy trappings, it's a place where I'd actually like to be. Wide fertile plains, farms and crops, cool and clean rivers flowing through green hills and forests. It's a strange combination of the Elysian fields and Valhalla (because it's hard to go far without coming under attack).
More than once in Oblivion, I ended up walking around for its own sake. Not for quests or to find a new cave to clear out for XP, but because the world itself is beautiful. I'd never do that in Morrowind or Skyrim because there's so little to look at. It's escapism, pure and simple. To visit a better place, even if only for an hour. Where the air is clean and the grass is green, where the water flows and a cool wind blows. To rest your knees in the shade of the trees and just for an hour, to see the flowers.