I don't know. I have this year's Madone. And while it doesn't look all swoopy like an Orbea or DeRosa, it's damn fast, comfortable, stiff and stable.
On the one hand, it seems like change for change's sake.
On the other, I've always had this notion that curved tube shapes would be inherently stronger than straight, and that a monocoque carbon frame would be stronger than a lugged one. But what do I know?