I've been pondering over this for awhile and here's what I decided:
It seems like Bethesda has taken the Fallout ip and is running with it full-speed. Fallout 3 comes out, it gets several big dlc's, then they poop out New Vegas; all the while Elder Scrolls isn't even mentioned... from an end user's perspective, it almost seems like they've dropped it altogether.
If Fallout is going to be their new flagship, I vote they release Elder Scrolls V: Tamriel... an mmo. They wouldn't have to use that easily mod-able engine and could thusly develop or utalize a better, less glitchy, less Oblivion/Fallout-rehash product and create a more fleshed-out world.
No idea what the grand story would be or anything... mayhaps just a giant sandbox, skill-based type gaming experience... I dunno. >_>
Anyhoo, they can keep a small passionate team dedicated to that, while the bulk of them concentrate on their shiny new cash cow.