Could a pcie slot card do sata 3? Would it be fast enuff?

I know its impossible to future proof, but usb 3.0 pcie cards already exist, do u think its possible for a sata 3 pcie card or sata 3 pcie raid controller card? All this new tech coming makes me want the p6t6 ws revolution with 6 pcie slots, so I can upgrade later.