I see you have updated the 3xs video section (eg 3XS - X58 Slipstream), which is exciting.
I looked at Wiki about the Sata 6Gb/s, and it says that no current disks come even close to saturating Sata 1.5 Gb/s, but that it does improve speeds when accessing the disk's memory cache. Your spec defaults to "*Sata 6Gb/s Hard Drive Not Required*" with an option for "2TB Seagate AS Barracuda XT, SATA III 6Gb/s, 7200rpm, 64MB Cache". Would it make even more sense to stick some Solid State Drives into these ports, or is that not an option?
The spec also defaults to no SAS drive, but these are faster than the regular SATA drives, right? OTOH the SAS drives only go up to 1TB.