Clemens, great series on microcontrollers! I have a couple comments and suggestions about the topics you cover. First, you should look at BeagleBones. The latest, BeagleBone Black, uses a 1GHz ARM processor, 512MB DDR2 RAM, 2GB flash storage, Ethernet, HDMI, etc for $45. As far as I know, it's the best microcomputer available today. It is Linux based and perhaps more importantly, runs node.js. This device screams to be connected to the Internet!
I haven't watched past Part 2, but yet I'm looking forward to see what you do with Service Bus!