The decision may have been unwelcome in some boardrooms, but could hardly have been a shock. Supporters of the status quo - most notably Usdaw and the Association of Convenience Stores - mobilised a highly effective campaign among their members and in Parliament.
The arguments may be over for now, but the issue is unlikely to go away and the outcome will ultimately be decided by shopper behaviour.
Each side in the debate has published a slew of consumer research claiming to show public support for their positions. For that reason, perhaps it's best to rely on Retail Week's own entirely independent study, conducted last year by ICM. It revealed 53 per cent of people favoured longer opening hours on Sundays and support was especially strong among the young.
Because Sunday, regardless of restricted trading hours, is already one of the busiest shopping days of the week, it is likely there will be a gradual build-up of support - or at least a lessening of resistance - among consumers for more relaxed hours. In that case, instead of going out with a bang, restricted opening will disappear with a whimper, the change uncontroversial and unnoticed by most people. It may not happen next month, or next year, but it probably will happen.
Meanwhile, will some UK retailers take more extreme measures to get around restrictions? In Nova Scotia, Canada, where Sunday opening is also outlawed for stores above a certain size, there has been an intriguing attempt by retailer Sobeys to trade regardless. Sobeys divided its shops into separate businesses, such as Sobeys' Fruit Stand and Sobeys' Meat market, which trade under one roof.
Might we look forward to Asda Banana Booth or Next Shirt Stop?
Localisation seems to be one of the emerging retail themes of the moment. As we report this week, Tesco intends to give its Express convenience stores a more bespoke look, tailoring the look and feel of outlets according to their locations.
In Tesco's case, the change comes in response to local environmental concern and probably the growing anti-Tesco feeling in some quarters, as the giant grocer is accused of unfair dominance of Britain's retail landscape.
But localisation is also something Waterstone's might benefit from, as it digests Ottakar's.
Despite being a public company, Ottakar's always prided itself and adroitly positioned itself as a local bookseller, in tune with the neighbourhoods it operates in.
During the controversial takeover of Ottakar's, Waterstone's was criticised as the Tesco of bookselling. Managing director Gerry Johnson should do his utmost to retain the local feel of Ottakar's stores and import that attitude into some of his own shops.