Multiple sources confirmed it (or annouced before @RayLoyzaga) but he seems to be close to the family and have more details to come.

See https://twitter.com/search?q=%40malcolmt%20&src=typd for reactions

Jacob Kaplan-Moss posted it today on djanoproject.com:

https://www.djangoproject.com/weblog/2013/mar/19/goodbye-mal...

Indeed, just saw it and was going to add a link to it. Also, link to its own HN submission: https://news.ycombinator.com/item?id=5402137