Yeah; there's a wide variety of styles for tutorial videos, depending on whether the student has some software background but not hardware, hardware background but no software, creative background but no tech, tech but no electronics/software, etc.
I wonder if it would make sense to organize a sort of on-line "class" based on some series of existing on-line videos (Blum's, Freid's, Sparkfun's, etc) Each week the class would watch a particular video, try to do whatever was described, and start a forum topic (somewhere) to ask questions, discuss things, help each other, etc. (Sort-of the way Stanford is running their free on-line classes, I think.) The original video creator could participate, and maybe add videos to fill in holes that become apparent, but that wouldn't be necessary. You could be unfaithful, and supplement one creator's videos with material from elsewhere "This week we're going to watch MIT's video of a lecture on C looping structures, which isn't specific to Arduino at all."
The main problem is that the video tutorials seem to cover a very broad range. If you master all of Blum's tutorials, you'll know a lot about various obscure technologies that you might never use. And it could be tough to get the referenced parts.
(that, and it may be difficult to get "Teaching assistants" to cover all the classes. Still, my perception is that the number of people willing to discuss a topic in forums is much larger than the number of people with the skill and confidence needed to create videos, so it might work pretty well even with just the usual drifting mass of "experts."
A lot of tutorials seem to be short on "assignments." And of course actually grading/correcting assignments, or doing them in the absence of such feedback, is somewhat difficult.
It would be an interesting experiment.