DeepOnion will support SmartContract and many other new features. You can do more based on DeepOnion blockchain. You can go to the official page to see DeepOnion new features and roadmap. Some new features , like DeepVault, have already integrated into the current version.
DeepOnion will be the first anonymous coin that can do a lot of things on it.
NEO has most of these features, e.g. NEO filesharing and NEO browser. I don't think DeepOnion has anything special, it might be the anonymous version of NEO, but its anonymity will restrict its smart contract functionality. I don't think it has the potential everyone hypes it up to have.
NEO is not a community coin, as it is very centralized and controlled completely by certain people instead of the whole community.
While DeepOnion is a community coin, the whole community can use DeepOnion VoteCentral to vote the future developing and marketing of DeepOnion.