Hi, I am the author of http://www.gamesas.com/bgsforums/index.php?showtopic=1033023&hl= for MGE/Morrowind. I've just checked the shaders for OBSE, they are identical. This means most of the shaders for Morrowind can be converted to Oblivion easily. The problem is richness of variables and features we can pass to shaders with MGE,
yesterday we gain access to two new variables which led to this.
http://i51.photobucket.com/albums/f386/vtastek/morrowind/Morrowind2009/caustics/Morrowind-MGE02.jpg
http://i51.photobucket.com/albums/f386/vtastek/morrowind/Morrowind2009/caustics/Morrowind-MGE11.jpg
All HDR shaders can be converted to Oblivion easily.
Godrays need sun position to work, note when I first started the Godrays wip, those variables were not accessible too.

With enough brainstorming godrays might be added. I am not experienced with inner works of OBSE, I saw it uses scripts to enable shaders. I wish it was possible to add them as easy as MGE.
I will try something for you... Wish me luck.

Edit:
http://www.youtube.com/watch?v=yNNh2wY2SRM