Perrew can you measure the jitter from spdif?
Who will do the resampling and recloking?
I guess top engineers of top brands (dCS, Weiss, Esoteric, Wadia...) choose usb or firewire (along with anti-jitter devices) for hiresolution and these engineers had written history in digital the last years.
Now if this is possible and sounds good it is welcomed by me but not as an ultimate solution soundwise due to jitter-transfer problems.