This is all about what the consumer demands. On desktops it's just a simple PCI card today and motherboards will slowly show up with it so it is just a matter of time.
My old computer is still working, but it is showing it's age. I would like to replace it, but one of the things I have been waiting for is USB 3.0. It seems like USB 3.0 is right around the corner, but when will companies like Dell and HP start including it?