Katharina, I've been showing this around. People are overwhelmingly impressed. Several have said they want to see more using this set-up. I think they're right. using your laptop camera really works and i think the use of sign-language is really engaging, even if (and in part because) I can't follow it. Speeding sign language up and cutting it into edited bits is worth more exploration.
Because my son is learning sign language I wonder if you'd be interested in collaborating on a project after the break. If so just drop me a line.
This video is one of the most interesting things I've seen in ages.