Text is easier to search and faster to verify that it's actually what you're looking for. The disadvantage is that you've to make sure that the content is actually working (the code compiles and shows the actual thing you're explaining). It probably takes more times to make, but (in my opinion) it's time you spent that the viewer gains and that's the added value for someone that wants to learn. Also you can easily edit a text version if there are errors or need more precision. You can also embed small videos to explain something hard to show/describe in text form.
You need to make a little more up-front investment (like posting the first three lessons) before you can get a good measure, because search algorithms will make sure that nobody visits your site to begin with if it has no content. I would likely read the whole first page of almost anything and only get to lesson three if I'm interested in reading the whole thing at once.
As the user, I would hesitate about giving out my e-mail address to a random stranger on the internet without even knowing what I was signing up for. Before I give my e-mail to a newspaper to access more articles using targeted ads, there has to be a large amount of quality content consumed for months before I even consider signing up for free. Personal data is treated just like real money.
Customers who sign up for something that doesn't exist yet without a detailed description are usually clueless about their own needs (trying every language but settling with none) or thought it was something completely different (like thinking that C is a dialect of C#).
The real value of video content as a learning resource for programming, is the "live" aspect of it. As is the case with HH, you have the chance to get into the mind of the programmer, how he thinks about structure, refactoring, dealing with bugs and issues and, most importantly, that they do lots of mistakes! Apart from that, it doesn't seem like the most appropriate learning resource, and it's better suited to application learning like 3D modelling or music production.
You're right that there's renewed interest in systems programming, which means you'll be competing with others who have a better landing page than you (or already have content, or already have a proven track record). <..> the more competition, the better
A budding game developer and programmer