MDT 2008 Update 1 includes new capability for OEM preload scenarios, a revised System Center Operations Manager Management Pack, bug fixes, and revised documentation.
MDT 2008 Update 1 enables deployment of the following Microsoft products:
Windows Vista Business, Enterprise, and Ultimate (32 and 64 bit) RTM and SP1
Office Professional, Professional Plus, Enterprise, and Ultimate 2007
Windows Server 2008
Windows Server 2003 R2 (32 and 64 bit)
Windows XP Professional with Service Pack 2 and Service Pack 3 (32 and 64 bit) or Windows XP Tablet PC Edition
Download it here, and read more about the update here.
Been using MDT 2008 for about 8 months now and have succussfully built a number of solution for my clients. Taking it a step futher, I have also designed zero touch deployments through WDS without SCCm. My web site explains the process as I have published a number of step by step procedures. Check it out..