John Hall, Technical Certification Developer over at VMware says VMware will announce new VCP certification that will apply to the upcoming vSphere.
There is no time limit between when you take the class and when you take the exam. The only thing I will say is that at some point this year we will announce a new VCP certification that will apply to the new release of our datacenter product. The training you took will apply to the VCP on VI3 certification exam, but there may be some additional requirements in order to apply your training to the newer certification. Even after we announce the new certification, you can still achieve the VCP on VI3 certification using your existing training.
John also has written several documents regarding the VMware Certified Design Expert (VCDX) certification which can be found here.
