Toyota introduced a pair of brand-new engines in Japan today, that it says will eventually spawn 14 different variants by 2015. Where these two engines stand out in today's world, is that neither mill boasts direct injection, and both are naturally aspirated.
First of all, what the heck is the Atkinson Cycle and why should we care? Naturally, it's a bit complicated, but basically in a modern Atkinson Cycle engine, the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold and allowing for a smaller compression ratio than the expansion ratio, making the engine more efficient with a slight reduction in overall power. Consult the all-knowing Wiki for more on that.