I think having a set of four mans that had the identical layout, like an additional mechanic or two on each of the bosses, while everything does more damage with more health - that could possibly work as a Savage instance.

I think what's missing is the higher tiered dungeon rather than just a boss fight as having a harder 4 or 8 man instance tier (like a Savage) rather than just boss fights would be good for the game. I don't want to have JUST boss fights, I like actual instances that you have to work on.

Then again, instance design for FFXIV has always been it's weak point, so I'm not going to get my hopes up....