I generally agree with your points, however, if I recall correctly, iTunes's window controls/style changed slightly before Leopard, and when Leopard was released, everything lost its white/pinstripe style and looked like iTunes. I think what we're looking at it is what every window in Lion will look like.

On the issue of dragging windows, I think that Apple is a bad boy that doesn't care about convention and wants to re-invent this. Right now, users have to know that only a specific narrow upper border is draggable. With any blank space replacing that tradition, users don't have to think about where they grab a window as long as they hit something gray that isn't a button.