SATA III, USB 3.0, PCIe 3.0

it will be a long time pcie 3 has been delayed until Q2 2010

ASUS has a work-around for SATA/6G on their latest P55 motherboards;
scroll down to the block diagrams here:

http://www.pcper.com/article.php?aid=769

Note, however, that there is still a theoretical bottleneck
at PCIe x1 Gen 2, which supports only 500MB/second
in each direction, whereas SATA/6G @ 10 bits per byte
supports 600 MB/second.

So, this workaround is not ideal, but it should make
a difference for the first crop of SSDs that will have
a 6G interface.

Seagate also have a Savvio 2.5" HDD model 15K.2 with SAS/6G support:
http://www.seagate.com/www/en-us/p [...] vio_15k.2/
but this is a 15,000 rpm rotating platter with a practical data rate
hovering around 150-160MB/second, directly under the read/write heads,
which is just now saturating SATA-I (150MB/second).

Hexus.net reports that ASUS is also developing
an add-on controller that supports SATA/6G,
using the same chips -- with probably the same
theoretical bottleneck of 500MB/second (as above):

http://www.hexus.net/content/item.php?item=19975

See also Intel's RAID controllers model RS2BL080
and RS2BL040 ("Big Laurel 8" and "Big Laurel 4"
respectively): these are enterprise-class SAS/6G
add-on controllers available now from Intel and
from LSI under the MegaRAID brand name:

http://www.tomshardware.com/review [...] ,2392.html

Based on the published specs, these Intel RAID controllers
should work at max bandwidth in all existing x8 PCI-E 2.0 slots.

MRFS