The page http://www.digitalmars.com/d/download.html still contains the old link to GDC. I suggest updating it to the new link, which is: http://bitbucket.org/goshawk/gdc/wiki/Home There's also a (correct) GDC link on http://www.digitalmars.com/d/1.0/index.html, maybe a common ddoc variable can be used or something to prevent this happening in the future.
The page mentioned above now contains the new link.