Well, I have written a couple of research papers in D as have others.
http://www.digitalmars.com/pnews/read.php?server=news.digitalmars.com&group=digitalmars.D.announce&artnum=13337
http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.announce&article_id=9466.