I've seen this on the forums of chess.com, just wanted to share here too. It seems Magnus has started a chess blog of his own (note that this is different from his father's blog which is not updated for a while). my source: http://www.chess.com/forum/view/chess-players/magnus-carlsen-blog
the blog itself:
This is not the absolute confirmation that it's is the real carlsen but someone mentioned this is part of the sponsorship agreement he made with the company that runs the site, I am convinced.