Bang goes my idea of sticking one of these in my nforce 650i based board.

Well, yes. Did you think all those pins for memory would fit in 775?

Didn't they ever read Ivor Catt?

How about 3 pins per bus, data in, out and clock?

Easy to make the buss tracks all the same length and 400GHz data clock is possible (= 80GBytes / second duplex)

Three pins for 64 bit PCI @ 66MHz is only 4.224GHz clock

MUCH cheaper packages and motherboards.

No reason not to have serial DDR3. It (serial interconnect) was done with PATA/IDE/ATAPI and Wide SCSI.

Admittedly you might need teflon PCB, but two layers (signal/power on top, ground plane on bottom) would do.