Download Link: http://www.microsoft.com/en-us/download/details.aspx?id=40796
What’s changed: http://download.microsoft.com/download/B/F/5/BF5DF779-ED74-4BEC-A07E-9EB25694C6BB/Whats%20New%20in%20MDT%202013%20Guide.docx
Major points:
1. No XP or Win Server 08 support.
2. Uses WinPE 5.0.
3. Deploys Win 8.1. http://www.microsoft.com/en-US/download/details.aspx?id=39982
Luckily, the MDT 2012 Update 1 link is still alive as well. http://www.microsoft.com/en-us/download/details.aspx?id=25175
/Brian G