Yes, this has been discussed before, and it just doesn't look feasible at any reasonable cost.

I'm thinking of a different approach. Most of us are VERY happy with the audio performance, but wishful for more memory (and therefore more software features) and perhaps a faster interface (100BaseT or USB2). This is all doable, with a daughterboard (with memory, CPU, and 100BaseT) that connects to the existing mainboard via the IDE header or an internal ethernet/USB cable...