Datacoin is proof of work where the data is stored in the blockchain. Bitcloud is proof of bandwidth, a completely new concept. We don't store all of the data in the blockchain, so we can scale to handle videos, audio, and bigger types of data.
Datacoin dev is working on personal (node) chains, so that the main chain will only store indices and meta data. Files, pictures, movie clips etc will be on the node chains. This is to avoid bloating the main Datacoin blockchain.
Datacoin dev has just finished Datacoin blockchain HTTP server:
https://bitcointalk.org/index.php?topic=405992.0;allInteresting. Last time I checked on that project personal chains were theoretical. Glad to hear they made progress. Having said that, I think they would still have problems. Can users stream videos from the blockchain? If so, how is the bandwidth paid for? Another difference is that Bitcloud can potentially be used to bootstrap a brand new mesh network with profit incentive in the future. "Mining" bandwidth instead of storing meta data in the blockchain seems like a better option.