Yup, two biggest obstacles right now are scaling and security/ease of use for the average user. I really do feel that a viable option will be easy to use smart contracts that can minimise losses that are deployed by the wallets themselves. That way we can retain decentralised ways of working. Although the average joe will want recovery options for when they lose their private keys.. Not sure how that can be implemented. I know this is one of the things EOS will be doing though but their solution is kinda centralised (correct me if i am wrong please)
RE: Wallets and security, what happens when cryptocurrency becomes truly mainstream ?