Wouldn't it be easier to use some kind of screen video capturing software like Fraps and put these ones on Youtube? Or the automated video capturing used by Xfire?
1. This way people could share their videos with just one link instead of having to collect a file, insert it into Teeworlds and execute the game just to see the video. It sure nice to have this function but it does tend to over complicate. Instead of hosting a file online which we need to collect and insert manually, there are already services on the internet which allow you to host the file as a viewable video.
2. This would also be a very good marketing tool, because people that don't play would happen to find it on Youtube and get interested in Teeworlds. The more members we would get, the more video content it would produce, which would then again produce more marketing. It's a powerful circle, ensuring a growing player base for Teeworlds.
3. It would allow people to keep Teeworlds nice and small by reducing the amount of custom content that sticks to our Teeworlds folder. Sure it wouldn't be much in terms of file size and can easily be deleted, but why not save the disk space while still having access to the content by outsourcing it to an external service?
Of course capturing and uploading recordings is still a time consuming job in it's current form, but if it could for example be implemented into the client it would solve this problem. It certainly has a potential to become more efficient then demo recording can ever be.