The ability to download from the NOOK® website and then sideload certain NOOK eBooks has been discontinued as part of a recent security update. Content that has previously been downloaded can continue to be sideloaded to NOOK devices. Customers can continue to access all of their content through the NOOK Library® on any NOOK device or Free NOOK Reading App™ as they have always been able to do. Customers can also continue to sideload other supported file formats.
Given the ease with which one can strip the DRM from the ebooks bought at the Nook Store, I'm not sure exactly what security is gained by blocking the direct download option. (Kudos to Chris Meadows for guessing that B&N would be foolish enough to use security as their justification).
But never mind B&N; let's look at what readers should do next.
How to Download Nook eBooks
You can still download Nook ebooks, but since we can no longer trust B&n to allow us access to our purchases I think you should go ahead and take the extra step of stripping the DRM as well.
Whether you choose to take that step is your business, but how you go about it will depend on how you read Nook ebooks.
For example, if you read on a Nook ereader, you can use the DRM-stripping instructions I posted in late 2012 to automatically transfer your ebooks off of your device and on to a computer via a USB cable. I updated those instructions in late 2013, so they don't quite match the current version of Calibre, but they can still be used as a guideline.
If you don't have a Nook device, I think your best bet would be to install either NookStudy or Nook4PC and use those apps to download your ebooks. Of course, they can't download everything, just the ebooks which they can open ( N4PC does not support digital comics, for example).
Neither app is supported any longer by B&N, but you can download ebooks - and then you can strip the DRM.
But what if you don't want to strip the DRM, but simply want to download the ebooks? In that case, you might want to consider a handy little userscript for Firefox and Chrome.
B&N's change in policy has upset a lot of people, and a couple helpful souls over at MobileRead have dredged up a userscript that adds a download link for each ebook on your My Nook page. It's really easy to use, and it doesn't do anything other than help you download an ebook. It won't strip the DRM, but it does give you a copy of your purchases.
You can find the script at this link. I got it to work on both Chrome and Firefox. As you can see in the screen shot below, it adds a download link, not a button.