note that the macbook doesn't have the dedicated video card capabilities for aero functions either (which if enabled will greatly reduce battery life)
Well technically the Macbook does have a dedicated graphics card, it's just integrated. It doesn't have dedicated graphics memory for sure but that's got nothing to do with the graphics card itself.
Also the graphics cards in all Intel Mac's support Aero at a hardware level.
Aero is automatically turned off when on battery power unless you change the power settings. Also Aero has the same effect on the battery on all laptops, not just ones with integrated graphics.