I've found that some motherboard software CDs/DVDs can be booted from to preload SATA and RAID drivers before you start the Windows installation. Not sure how well this works or how efficient it is, but just something I noticed more recently.
I do not think you mean actually booting off of the software CD that came with the motherboard.
You may mean booting off of an OS CD and using "F6" during setup to install the drivers from a CD at that time.
I mean what I said previously... Got my sister a midrange Asus board and after using the disc to install the chipset drivers, etc. I left the Asus DVD in on reboot, it booted from the disc and gave me the option to load RAID drivers.
I have yet to do a RAID setup, so what I saw may or may not work in the same sense as the slipstreaming, but just wanted to throw it out there as it may help someone out. Might be a fairly new software trend with Asus and other board manufacturers since boards with RAID capability are becoming more and more common.