I'm familiar with the problems associated with storing larger files in Datacoin, but are personal chains a solution to that issue? I've been thinking that personal chains would be similar to our system of moderators. Nodes basically subscribe to a moderator, and then the moderator decides the kind of content that can be stored on the node. This means that all of the nodes aren't storing the same data, and they can make sure they are still following the laws in their local jurisdictions.
The ideas are sort of similar, although the details of what is possible will only become clear as the code gets released.
What is very nice is that various groups are starting to realise that crypto-currencies only have value if they are backed by the assets of the p2p network - bandwidth, data/file storage and cpu cycles. Projects like Curecoin and Gridcoin are trying to base themselves on cpu cycles, while Datacoin monetizes file storage. Interesting that you have focused on bandwidth.
My feeling is that open source rarely duplicates, and that different groups tend to work on different aspects of the ecosystem. For example, if your WeTube was built on top of Datacoin and Datacoin HTTP server, we would probably have a winning formula. No wasted efforts, and fruitful cross-fertilization of ideas. The Datacoin protocol would be tweaked to suit different media, and vice versa.
If you are worried about Datacoin "early adopters" I would say the coin is actually super cheap and can still be easily mined. It is only 2 months old. And 2 billion will be released over the next few hundred years. So plenty of time to get on the train.
Just my honest opinion.