Though very cryptic on information, Nvidia dropped several hints as to what Optimus could entail. Making a point to mention both performance and battery life, Nvidia indicated that Optimus will be "seamless and transparent". Some theories suggest it will be an improvement on hybrid graphics, where discrete and integrated GPUs share a single system.
You could also speculate that Nvidia is planning a new notebook platform altogether. Unfortunately with such sparse information, it is difficult to say where they are actually going until more information is revealed.