I've been pretty busy with things this past year and even though I started working on the DE tutorial, I never really found the time to continue working on it. However, this next year looks promising in the fact that I'll have fewer classes to take, implying that I'll have more time to work on the site and this tutorial. Originally, Ackbach and Fantini had volunteered to help me with this (and I'll assume they're still onboard once things get moving again); if you'd like to be a part of this, feel free to send me a PM and I'll get back to you more about what I have planned for this tutorial.
I still have preliminary exams to pass and that will take up most of my time and attention in January. Thus, the DE tutorial will have another update sometime in February (most likely the first week; sooner if I get promising results on my first two preliminary exams).