T-Mack, my machinist buddy, whom you know, says that without forging, this frame will be either too weak or too heavy. Weak, because of the grain structure of aluminum and the inherent weak spots. Heavy, as they won't be able to machine enough material out to maintain strength. Can they efficiently forge blocks that big? Can they mass produce a product with that much machine time?
And this whole environmental push they are trying to create is a real funny one, as they probably don't realize the huge footprint that mining metals entails... and that's just from mining trucks alone. Pound for pound, I would guess that carbon fiber actually has less of an impact from a manufacturing stand point.