I never read the Designer Diaries before because I didn't want to be spoiled about gameplay, etc.
http://gamespot.com/gamespot/stories...688004,00.html
Now that I read them, I can't believe how much of the original game ideas were cut out! Granted, they may have been biting off more than they could chew for certain deadlines, but if MO was everything that they originally envisioned, OMG it would have been the most amazing game out there.
Not to say that MO isn't great as it is, but the gameplay sounded so much more engaging (from a Quarma aspect especially) than the final product.
Hopefully, some of these will be put into ME (there was some mention in the Diaries that we'll get to know more about Sligs than we ever did before (?!?)).