But as you certainly know not all shaders are created equal and the same goes for CPU architectures. I also don't really know where you found the numbers for the shader clocks, they may very well be running faster than the core speed, but the discrete chrome 530 gt is clocked at 625MHz so I'd expect the core speed to be lower than that in an IGP. You've also got the shared memory bus (despite it being dual channel DDR3.... potentially as it supports from single channel ddr2 to dual channel ddr3), so it's not going to have anywhere near the bandwidth of this discrete card, which in gaming situations looses out to the lowest end discrete cards from it's competitors.
http://forums.s3chromezone.com/phpBB3/viewtopic.php?f=36&t=591
I know it's conjecture to say that the discrete version is slower than it's discrete competitors so the integrated version would follow in suit, but I don't think it's entirely inaccurate. The ION has the strongest GPU of them with a 9400M class IGP, while AMD's HD3200 integrated probably looses out (but a slightly upclocked 4200 may be plenty to beat it). That being said, we're considering platforms, and the Nano is an Atom competitor, not a CULV/Neo competitor. While it is computationally faster clock for clock than an atom (some benchmarks say by a fair amount, most say by a little) the Neo and CULV chips are based of of *real* desktop architectures.... so they will be much more computationally capable and number crunching is what you need for multimedia.
In other words, no clear winner comes out on top for these platforms, intel and AMD's options can duke it out for overall computational power while the ION takes the cake for graphics horsepower. Still if they can get a decent price, good availability, and decent drivers VIA will at least be a competitor this time around.
Also I thought the ION could do DDR3 (and could do dual channel) but it wasn't being implemented much in the marketplace.