Replied to you on the other thread, but I'll say it again here. Since they have joined with Amazon, you'll be seeing Waterstones screensavers according to this article:
http://paidcontent.org/2012/09/12/wa...he-bear-traps/
It states:
At yesterday’s IPG event, Daunt revealed a few more details about Waterstones’ Amazon partnership. ”Waterstones-specific Kindle screensavers, bestseller lists and a Read For Free offer are among the plans,” The Bookseller reports.