Jetro informed me that Hispabrick Magazine has just released their eighth issue. You can view the magazine online using this link, or download the complete PDF by going to this link, and clicking "HM008 - English". Each of these options are free of charge.
Hispabrick Magazine is about LEGO in general, but this issue is especially an interesting read for MINDSTORMS owners, as several articles focus explicitly on MINDSTORMS NXT.
You will find an article about the MINDSTORMS Community Partners, as well as interviews with three of them, including Xander Soldaat, Fay Rhodes and me.
Furthermore, you'll find a tutorial: "A PID Controller for LEGO MINDSTORMS Robots". Finally, the article "Actuators for the NXT" talks about several actuators, including the new FIRGELLI Linear Actuators.
The issue also covers non MINDSTORMS topics, like Technic, Space, as well as reviews of new LEGO sets. You may also want to read the interview with Kjeld Kirk Kristiansen, the owner of The LEGO Group.