There’s not much detail, but there’s pictures, which look pretty fantastic…
The Firewire Electric Guitar (They’ve made the pictures a bit too wide for the space they’re in, so you might have to scroll down towards the bottom to see the article.)
It’s an electric guitar, but like the Line 6 Variax guitars, it has hidden pickups to track each string separately. Rather than using that in the guitar to model other guitars, though, this uses a firewire port to output six audio channels. What you do with it after that, presumably, is up to you, but I imagine you could potentially apply different effects or mixes to each string, or place each sting in a different place in the stereo mix.
It would probably even be possible to feed it into a box that would do similar modelling to the Line 6 guitars, but externally rather than internally – but someone would have to develop it.