Yes, a very
long thread is here.
In a nutshell, with 5.4.2 the PW2 will show
ALL of your Cloud Collections, whether you want it to or not. And all books/docs stored within the Cloud will be displayed within Collections on the PW2 but will be greyed out if they are not also on the PW2. Any changes (renaming, deleting, etc.) you make to Collections from your PW2 will be reflected on all applicable devices and apps. So no more unique Collections for different applicable devices/apps. It is a real mess.