The 400M series features seven new processors, including the GTX 470M and GTX 460M monsters aimed at "enthusiast users," as well as the GT 445M, GT 435M, GT 425M, GT 420M and GT 415M, intended for real-world use.
If you're questioning why NVIDIA is releasing five GT GPUs, you're not alone. While there will likely be a noticeable difference between GT and GTX models, the variations between any two of the GT processors are likely to be minimal.
Like all things currently graphics-related (or so it seems), the 400M will support stereoscopic 3D video. Those of you with a 3D TV will be pleased to know that the 400M GPUs include NVIDIA 3DTV Play software, which enables 3D content playback on compatible TVs.
More important, though, is the inclusion of NVIDIA Optimus, a technology that switches the GPU off in order to conserve battery power when its not processing graphics-heavy materials. This allows for flexibility in notebook longevity, while not degrading performance.