We've just learned that ATI's SB800 Southbridge, the one scheduled for second half of 2009, is supposed to support brand new SATA 6Gb/s or better known as SATA 3.0 standard.
AMD will be among the supporters and we believe that the hard drive industry will follow. We are sure that SATA 3.0 devices will run a bit faster and you can forget about doubling your performance simply from going from SATA 2.0 to 3.0. Theoretically, SATA 3.0 has doubled the bandwidth that jumped from 3 Gb/s to 6Gb/s and this should bring some performance improvements; but we wouldn't expect huge leaps.
We are sure that Intel and Nvidia, the other major chipset players, will support SATA 6Gb/s as well, but we are not aware of these plans at this time.