The Shivering Isles Expansion for Oblivion was nothing short of spectaular, the reinvionsioned twist on the classic Elder Scrolls landscape and story telling was welcomed with open arms in my house. However despite all its glory, one shortcoming i noticed was the fact that after you defeted Jygalag (SP?) and stopped the graymarch, blah, blah, the powers you obtained from usurping the madgod's throne were not carried back into the original world of oblivion. I.E. Summoning of Golden Saints and other Shivering besties, the weather change spell etc.

I was curious as to whether or not this was purposefully left out or if I was left out due to program impossiblities. Does anyone know? And can/should similar content be alowed back into the world of skyrim?

All of those things that didn't carry back had nothing to do with programming limitations. That was a design choice by the devs. I'm all for summoning the cooler Daedra (If I have to summon one more damn scamp....) but I doubt a lot of those will get carried over. It would be too much work for them to design new models for things like the Golden Saint for them to just be summons. They would have to be regular enemies too.