This seems like a good project.

I believe you have already done your research on Youtube's CDN and its algorithm of distributing videos based on popularity? (will be very very helpful in reducing the network overhead, and transmission delays.)

If not, you should research a little bit about Youtube CDN network on how it realizes pseudo-decentralized architecture (from the infrastructure's point of view). Might help you push your development a little further.

Apart from that,  i am overly curious and interested on how are you going to overcome the very-very-very-high network bandwidth such a project will demand. There are ISP's out there who are actively throttling Video Streaming service speeds. (this will be your biggest challenge.)