This comes from the Nook newsletter. Big news:
We are writing to announce an important change to our NOOK Service that will affect NOOK Press vendors publishing content in the United Kingdom. Effective March 15, 2016, NOOK will no longer sell digital content in the United Kingdom. The NOOK Store on NOOK devices sold in the UK, on the NOOK Reading App for Android, and at www.nook.com/gb will discontinue operations.
NOOK customers in the UK will continue to have access to purchased NOOK Books until May 31, 2016. After this date, NOOK has arranged for the award‑winning Sainsbury’s Entertainment on Demand to provide access to customers’ purchased NOOK Books.
There is no change to NOOK Service or NOOK Press in the United States. If you are an author based outside the US in a supported country, you can continue to use NOOK Press to publish digital content in the United States and receive payment in your local currency.
After the March 15th, 2016 deadline, titles will be available for sale in the US only, with a list price in USD ($). For new titles, you will no longer be able to set pricing in British Pounds (£) or Euros (€). For existing titles, no changes need to be made by you at this time. If you are making a change to the Book Details, however, the Sales Territory Rights will default to “United States only”. Your sales reports will continue to report any sales of titles in the UK that were sold prior to the discontinuation date.
To review more information about this change, visit our FAQs page.
Repeat: there is no change to the U.S. store. For the moment.