In the back of my mind there is a vague notion to try and utilise bigger bottom bracket bearings. I dont think there is much need to go into why, as there are clear and obvious benefits. In addition, an internal system would be nice in terms of longevity (the outboards are ok, but not the most moisture resistant). Coupled with light weight and high stiffness and bobs your uncle.
Here is a thought...
Look closely. That is an ebb equipped cannondale 29 er frame built for commuting...with a cannondale si crank and bb30. The ebb was machined to accept the press in bearings. Not bad eh? read about it here...which is where i lifted the pic from. The only downside i can find to trying it out is the cost of those cranks - around £500. But, with fsa, truvativ and others bringing bb30 cranks to the market (including it is rumoured shimano dura ace ones) there should be more choice soon.
Some interesting threads have also surfaced looking at fitting bb30 cranks to normal shelled bikes. Seems like a lot of fuss, and some of the benefits are lost, but interesting nonetheless.
weight weeneis thread