I would love to see official support for Salesforce's new State/Country Picklist functionality. According to Marketo Support, this feature isn't currently supported and they recommend not enabling it. (I've been told the same for another 3rd party SFDC app, so I guess the feature is still too new.) Please add this to the roadmap Marketo! This SFDC feature would be a great way to ensure standardized state and country information in our databases (both SFDC and Marketo).