Actually, I've done this - I still have the setup. Eddy current resistance is nothing new - I think I first learned it in HS Physics class in 1972 - so it's been around at least that long.
I mounted magnets on a strip of plastic and put them next to my rollers. Rollers are silent - but the magnets provided a nice resistance. You can do the same on any alloy wheel with any trainer, btw. Just disengage the resistance roller.
SO- for those if us that have PowerTap alloy wheels , this is pretty good way to get a quieter, linear resistance, trainer.
The downside (again, I've done this) is you need to spin the wheel pretty fast to get enough resistance. Or get much stronger magnets than I had. The higher rpm of the wheel makes nearly as much noise as using a roller, btw. Try it.
Why? Most people's wheels are not true, nor balanced. So when you spin more than 30kph or so (where the resistance actually starts coming in) , the wheel starts wobbling and rattling. With no tire contact dampening, it feels like the whole bike is going to explode. Well, not quite, but it definitely sounds and feels 'not good'.
FWWI - the GrowTac trainer works beautiful in this regard. You ride the rear wheel on 2 rollers, they have awesome (Japanese) bearings, noise is minimal and the resistance loading (also magnets) works great as it's applied against a much faster turning counter-wheel.
I'm not totally negging this project - but, there are quite a few reasons why it's jus kind of 'meh'. Try it yourself. Go to Tokyu Hands (or Amazon) buy some magnets and position them close to your rim. I think for less than $50 you can get a pretty decent 'silent trainer'. And if you have a PowerTap wheel - voila! You have real power output and not a kludgey 'virtual power'.