From the Microsoft certification site (http://www.microsoft.com/learning/en-us/sql-certification.aspx):
Q.How will the updates for SQL Server 2014 impact official Microsoft training and certifications?
A.SQL Server 2014 certifications will only be offered at the MCSE level. The new product features focus on performance tuning and high availability and are best suited for the MCSE level. As a result, the following updates are planned:
•The MCSA: SQL Server 2012 credential and associated exams (461/462/463) will remain in market without any alterations. No MCSA: SQL Server 2014 credential will be offered.
•In March 2014, the MCSE: Data Platform (464/465) and MCSE: Business Intelligence (466/467) exams will be appropriately updated with SQL Server 2014 topics. The exam numbers will remain the same.
At least one month prior to the update, details on the original and revised exam objectives will be made available for review in the Skills measured section of each exam detail webpage.
•Also in March 2014, recertification options for maintaining the MCSE credentials will be made available.
I suspect that this is the reason why none of these training kits (464,465,466,467) have been published yet since they intend on updating the objectives and exam content in a few months.