To understand how the new DPRK Constitution relates to the powers of the National Defense Commission, you can consult my entry on the NDC here.
The North Korean press issued the October 2009 editions of its two overseas monthly magazines, Korea and Korea Today, and the Korean-language monthly Kumsugangsan. These publications are by no means a realistic representation of workaday life in the DPRK (even among the elite), but the photography is quite good. The October edition of Korea includes an article on H1N1 that features the by-line Kim Kyong-hui, who may or may not be the sister of Kim Jong-il. Finally, I will add a critical note (critical and criticism does not necessarily connote a negative): the English writing in Korea and Korea Today is actually quite good. All obvious hagiography toward the General-Secretary and the KWP aside, having read these things for eight years, I have noticed in the last calendar year, or so, that the quality of writing has improved dramatically making what used to be tedious chore all the more trenchant.