As for Oblivion, I first heard the cinematic trailer theme that was likely just gotten from some other game (although I still have no idea which game, maybe you guys could help me http://www.youtube.com/watch?v=c0AmyQJafnU), similar to the Icewind Dale theme in the Neverwinter Nights trailer or the Prince of Thieves Overture in a Forrest Gump trailer. So, when I heard the Morrowind theme revamped later on, I initially thought it was a bad move by Bethesda - mostly because I loved that trailer theme as well. But then suddenly - "Behold, in darkness, a doom sweeps the land" - the theme cascaded into an opera as the camera span around the white tower of the imperial city. Once again, shivers went down my spine.
Now, Skyrim is keeping up with traditions. Never using the exact same theme, but improving on it and adding sound to it that fits the current game and setting. For Skyrim, it hits right at the spot to add the dovahzaan monks singing in the background and the building up of energy until the climix when the Dragonborn shouts "Fus Ro Dah" and we hear the familiar Elder Scrolls theme once again, albeit under a different guise.
Bethesda:
This is one of Jeremy Soule's very best compositions. As such, I think that you should create a new tradition for the Elder Scrolls, although it kinda seems like you already did. Let's rename this grand theme "The Elder Theme" and let it be the main theme of all future Elder Scrolls major titles. Morrowind started it, Oblivion grandeured it and Skyrim hit us like a freaking truck.
Let's keep this theme as one of the key features of all future TES games.
Discuss!