If you are upgrading from BDD 2007 (any version) to MDT 2008, the instructions are covered in the "Getting Started Guide" included with MDT 2008.  So I won't repeat that discussion here.  I want to focus on the new scenario, upgrading from the original Microsoft Deployment to the new Microsoft Deployment Toolkit 2008.  Here are the basic steps needed when using Zero Touch with SMS 2003:

  1. Make sure you have a backup of your environment.  While I don't expect anything to go wrong, it's always a good practice to have a backup :-)
  2. Install the new MSI.  This will automatically upgrade the existing installation files, e.g. C:\Program Files\Microsoft Deployment Toolkit.
  3. Run the new Deployment Workbench.
  4. Click on the "Distribution Share" node and run the "Create Distribution Share" wizard to upgrade the scripts and tools in the distribution share directory.  You can choose to backup the existing scripts as part of this.(After doing this, you may need to press F5 to refresh the nodes under the distribution share node.)
  5. Update each OSD deployment point.
  6. Modify the list of files needed in each OSD program's custom actions using the SMS 2003 admin console, then update the distribution points.  This is necessary because there are some new files included in MDT 2008, and some old files removed (related to servicing stacks).
  7. If you are using a "ResourceRoot" package or directory, make sure this directory contains a full copy of the "Servicing" directory in the distribution share directory.  (Update distribution points if you are using a package.)  This director contains the servicing stack files for Windows Vista (RTM and SP1) and Windows Server 2008.  Without these files, MDT will be unable to inject drivers, patches, and language packs.

MDT 2008 does not require Windows AIK 1.1 if you are using only Windows Vista RTM or Windows XP; Windows AIK 1.0 is fine for these.  But if you are using Windows Vista SP1, you need to upgrade to Windows AIK 1.1.  (If you don't, as soon as you add a Windows Vista SP1 image, you'll start seeing warning dialogs.  They won't go away until you do upgrade.)  The steps needed to upgrade to Windows AIK 1.1 are:

  1. Uninstall Windows AIK 1.0.
  2. Reboot.
  3. Install Windows AIK 1.1.

Note that the steps above are very similar to those used for Lite Touch (see the previous post at http://blogs.technet.com/mniehaus/archive/2008/03/21/upgrading-to-microsoft-deployment-toolkit-mdt-2008-lite-touch.aspx), not surprising since most of the MDT scripts and tools are shared between these two deployment methods.

That should do it.  Now you're ready to start with Windows Vista SP1 :-)  (SMS 2003 doesn't officially support deploying server operating systems, so I've left Windows Server 2008 out of the discussion.)