Plus the dual-core actually helps battery life because it divides up tasks and uses fewer resources at any given time.
Sorry but that isn't right. Dual core does not use less, it uses more. You have to power two processors, and their clocks are ticking even if you are not using the processor cycles. The only thing that affects current draw is the actual core's design, and whether or not it's running w/ the low or high multiplier (whcih changes in real time based on demand).
If the bionic uses less power on the CPU, it has nothing to do with being a dual core and everything to do with the architecture within each individual core.