Just like GCD in Snow Leopard.. it never caught on and I assume the same will be with the firepro drivers. Software always trails the hardware.. Hardware is there, but drivers aren't which take advantage of it.
wondering if 10.9 will bring support to 5,1 or earlier machines for FirePro cards? if software is going to be written to take advantage of the cards in the new MacPro then maybe "add-on" cards for older machines would be possible? that is, assuming 10.9 can be used on a 5,1 or earlier machine...