Pci-X is still developing however.. (I dont understand why, unless there is
more reliability there)..
you can get SATA Pci-X cards .. the PCI-Express stuff will happen with
the Nforce 4 chipsets (or so I hear) .. I have seen some VIA roadmaps
showing the 800pro having express support (but it doesnt show it now) so I
am guessing they have push'd it back for their 900 series.. This is
something I want too, but I want to see some of the express spec (right now
it's somewhat limited as to what I can open and read on the psig site)

Old technologies take a very long time to die, remember how long ISA buses
were around. PCI-X cards will also work in 3.3V PCI 66MHz slots and there
are millions and millions of them out there. So PCI and PCI-X will be
around for a long time. There is talk of a PCI-X 2.0 but I doubt that it
will actually happen. To push PCI beyond 133MHz will require a change in
logic levels which would break it's compatibility with older PCI buses,
once you make it incompatible the you might as well go with something
completely different like PCI-Express. More importantly Intel has decreed
that the world will be PCI-Express not PCI-X 2.0. Intel wants to force the
world to be entirely PCI-Express but that won't happen for a while. Even
if Intel takes PCI support off of their chipsets, VIA, SIS and Nvidia
won't. Broadcom probably won't take it off for a while either.