interesting, but somebody better tell his dad to update the blog ! the latest is the June's blog.
Magnus Carlsen Blog

wow, that's gold! thanks for sharing. it does seem it's really Carlsen, but is there anyway we can confirm this?

Yikes, now that i think about it there's no proof that this is him :( I did get this from a solid member of the premier pro chess broadcasting and discussion site. In fact I saw this link posted more than once. (from members who I have known for YEARS.)
I would be strongly inclined to believe this is him but I have been wrong before.
Most chess fans know that Magnus Carlsen's dad keeps a blog detailing his sons activities - http://blog.magnuschess.com/ but something I've only learned recently and is perhaps not common knowledge is that Magnus has a personal blog too - http://arcticsec.no/index.php?button=blog&main_image=35 . Here he talks about the recent Tal Memorial and the current World Blitz Championships.