A new wave of tecnology is about to hit enterpise SQL SAN's. The humble flash disk scaled up to 1TB. In theory this gives incredibiliy low IO latency and eliminates the descrepancies between random/sequential IO and slowness due to a disk filling up!
The RamSAN from Texas Memory Systems claims 1TB of Solid State Storage with 3.2 million IOPS! http://www.superssd.com/products/ramsan-400/
Expect High end SQL Server systems to use this for tempdb and high hitting areas like the ReportServerTemp database or ETL staging disks soon.
I can't wait so I'm tryin to get hold of this baby for my trusty Dell 820 laptop with 64 bit SQL Server on it. http://www.reghardware.co.uk/2007/04/03/transcend_touts_expresscard_disk/
These solid state disks are also great for increasing Windows Vista Performance with the new "Ready Boost" feature