I wonder how many people find this sort of thing more useful than a text article with a few well-placed screenshots. I can easily see how a video can be handy when explaining some highly visual and interactive environment but in this case, you're mostly staring at a dude's editor or browser while he types things and clicks things. A dude with the accent and cadence of a cartoon hypnotist, no less. The effort expended in producing a screencast must easily exceed that of writing up the same information. Not to mention ease of addressability, indexing, updatability, etc, etc, etc.
I did felt like in a Kraftwerk concert sometimes. The idea of creating a screencast for showing how Capuccino works is great and I hope the author keeps doing this effort.
I don't find it as useful when learning something completely new, but it's been great watching railscasts once a week to pick up new skills. It fills in the gaps between screenshots.
I think that one or two solid, relatively short, screencasts can sell me on a framework or language... DHH's screencasts back in the day sold me on Rails despite his unique voice :-)
After that, something that is text-searchable is really preferable...
I started using Cappuccino on a project about a week ago now. I watched one Cappuccinocast, and then wished that some of the text-based Cappuccino tutorials were better developed. By now, I've found my way, though knowing Objective-C and Javascript really helped.