Currently, wave doesn't have any data mining features. Basically the functionality is the ability to do data discovery across single or multiple datasets.
There are some Salesforce prediction partners, however I think most of them essentially require the import and export of the required data, they perform a standardised algorithm of which you can then import into Analytics Cloud . There is no Predictive Analytics on platform.
With middleware you can import datasets onto analytics cloud that can be architected around Predictive and outputs from data mining. ( i.e. the automation of finding trends / patterns)
Black belt Training - Is essentially: Completion of the Analytics Cloud Brown belt, completing a full implementation, and have a case study with feedback from Client.
Salesforce Analytics is a productivity tool, this is a tool to support the greater data democracy by putting actionable data in the hands of lots of people in an organisation. Data Scientist --> Data Citizen . Essentially looking for actionable insight by the end user.
Im sure as the platform goes there will be partners, and features released that support predictive.