Some of the other exciting features being developed by Mastercoin include a decentralized betting exchange and using contracts for differences to create currencies that don't need to rely on a third party for physical backing.

One thing that needs to be pointed out about the Mastercoin protocol is the mastercoins on that layer also have their own value separate from bitcoins. This means that Mastercoin is also an alt coin. There are some interesting features that are being added to the Mastercoin protocol, such as the ability to mark certain mastercoins in a savings account where payments can be reversed if the are made without the address holder's permission.