A challenge for customers in OSD feature pack was having the correct drivers available for the hardware being imaged - both during the Windows PE phase and after the image was deployed and the new operating system booted. Further, customers were limited to only being able import NIC and Mass Storage device drivers. WIth SCCM 2007 the process gets much easier. Now, there is a 'drivers' node in the console that allow drivers of all sorts to be imported - resulting in a driver catalog. These drivers may be arranged into driver packages and easily imported into the WIndows PE images being used or used with an image being deployed - which is where we see the power of the driver catalog.
During the Windows PE phase of image deployment - and right before booting into the new OS, a step in the task sequence requests driver matching from the driver catalog. The hardware where the image is being deployed is scanned and a summary of devices sent to the management point - the management point then queries the driver catalog (the drivers imported previously) to see if we have matching driver(s) for the hardware. If so, the driver is returned to the task sequence and loaded into the image so it is available immediately when the system reboots.
All in all a very cool process and takes some of the 'guessing' out of building and deploying images.