HTTP on most residential networks has a higher priority than P2P.

Combined with the fact that Google use the Google Global Cache (GGC) service inside ISP networks, I don't see how this would be any faster on todays internet.

Cool idea and concept, but don't see it helping.

Wasn't Google working on some P2P protocol for Chrome?

Why would this extension need to access "your data on all websites"?

Probably because it can't say "your data only from Youtube".

May be to work with Embedded Youtube videos on other sites