Once again, Sony is looking for testers for a closed beta of a future PS4 software update, this one being version 4.00. Registration is open from now until the day it begins in February (to be eligible you must be over 18 and have a PS4 with an internet connection and access to a Master Account).
We still don't know what will change in 2017, but we can expect "overall PS4 UI refresh, Folders, the revised Quick Menu, and much more" in the update. Beta testers will get an email with the instructions on how to download the software update. As usual, everybody can roll back to the previous firmware at any time.
If you're interested, you can sign up here.