The Internet Explorer team described how to slipstream IE 8 Beta 1 into a Windows Vista or Windows Server 2008 image using the process described at http://blogs.msdn.com/ie/archive/2008/06/20/slipstreaming-ie8.aspx.  Here's the same basic process with MDT 2008:

  1. Download the needed version(s) of Internet Explorer 8 Beta 1.
    x86: http://www.microsoft.com/downloads/details.aspx?FamilyId=C3C6E8C1-BD91-490B-86F5-F3652DD691DE&displaylang=en
    x64: http://www.microsoft.com/downloads/details.aspx?FamilyId=D399733E-D4A9-44FD-821B-1C52D3C677E3&displaylang=en
  2. Extract the updates from the downloaded self-extracting installer files (into separate folders if you downloaded both platforms in step #1).
    x86: IE8-WindowsVista-x86-enu.exe /x:c:\temp\ie8x86
  3. x64: IE8-WindowsVista-x64-enu.exe /x:c:\temp\ie8x64
  4. Import the IE 8 updates into Deployment Workbench (right click on the "OS Updates" node and choose "New") by pointing it to the subdirectories you created above.
  5. Deploy an OS :-)

Here's what the updates look like in Workbench:

image