Keep in mind that when Cisco brings in the next versions in their certifications, there is a period where any exams completed using the old version, can be used towards your certification. So if you get your SWITCH exam done before the switchover date, it will still be valid towards your certification.
You can find out more about how this is done at this Cisco site:
Finally, if you have been studying for your exams, my suggestion would be to get as many exams done as reasonably possible before the switchover. The reason for this is that if you wait, you will have to go back and cover additional sections of the new certification tracks that may not have been included in the current exams. Ultimately it will take a little longer to study for.
I hope this has been helpful!