This is a happy, satisfied story. I have had an e-ink Nook since June 2010, and purchased a Color in January. Inevitably, my e-ink has been getting a bit less love recently, as the NC is better for reading in the dark, cold Michigan winter.
That said, the older Nook is still valued and used daily. Recently, my teenage daughter has been reading Septimus Heap on it. Saturday morning, she powered the Nook down, and it subsequently wouldn't restart. I followed all of the recommendations I could find in the forums here and elsewhere, to no avail.
Finally giving up hope, I took the Nook to our local B&N in Rochester Hills, MI. They quickly tested and verified its demise, made a quick call to ascertain its warranty status, and provided a new Nook. This allowed me to retrieve my NC from my daughter, leaving her satisfied with e-ink and me pleased with a solid customer service experience.
Kudos, Barnes & Noble. Good devices, excellent service.