Why would anyone want souped up graphics on a netbook? Good question. And we got our answer during a brief video demo with Nvidia today, who showed us its Ion platform (which combines 9400M graphics with an Atom processor) running on the eagearly anticipated Lenovo IdeaPad S12 (though it’s not this Ion-packing model, we’ve got a full review of the Lenovo S12). The good news is that the performance looks pretty stellar. The bad news is that you’ll now have to wait til the fall to scoop up this version of the S12, which will sell for $495. Lenovo had originally said “later this summer” in its May 25th press release. We’re guessing that this could be a launch netbook for Windows 7. Based on our brief hands-on time, we think the Ion-powered S12 will be worth the wait. The S12 we saw played a 1080p trailer of the Dark Knight (most netbooks can handle 720p but choke on 1080p), while the CUDA-enabled BodaBoom software transcoded another video clip in the background. We didn’t notice many dropped frames, and the S12 finished processing a 2-minute clip in about 2 minutes, whereas the typical Atom-only netbook takes 30 minutes to transcode a 5-minute clip. We still have high hopes for Ion, but we’re curious to if and when other big names jump on the bandwagon.