The VMware Certified Design Engineer certification will be available later this year. The certification involved taking several courses and exams, including:
Install and Configure
Design course (currently under development)
VCP on VI3
Enterprise Exam (currently in private beta)
Design Exam (currently under development)
Once all of this has been completed the candidate must present a defensible design to a panel of VMware Solution Architects for consideration. As you may guess, this is a certification specifically targeted for VMware partners that will be assisting VMware in design and deployment and is only intended for a relatively small audience. That being said, the Enterprise Exam, which has a number of live lab style questions, should be available to the public in the next few months and may become part of a mid-line certification between VCP on VI3 and VCDX. That is also under consideration.