There is really no good forum for this so I'm posting it here. (It's really only a suggestion/idea post that doesn't fit under any subforum)
The idea of downgrading a TES game is one I've had for awhile, but I haven't bothered to make a Morroblivion account until today to share the idea.
Basically, what a "downgraded game" would do is to let you play each game on the previous game's engine (or Skyrim on the Morrowind engine). I fully realize this could be a difficult task with having to re-do many meshes in lower rez forms, etc, but would be well worth it in the end. Also, I am aware that certain quests from, per se, Skyrim, could not be done in Oblivion due to different spellcasting types etc, but we could work around them by changing that specific function to something you CAN do to complete the specific quest.
These games on different engines goes along with my other forum post:
http://morroblivion.com/forums/skyrim/skywind-development/4429
Food for thought.

Heheh
It can't be TOO bad since it's an introduction of my idea :P