FWIW, there's a Nook app for Mac, PC, Web, iDevices, and Android devices.
http://www.barnesand...-apps/379003593
It may disappear in time, but you'd hope that if they did kill off the service they'd make provisions for unlocking the books or something. I believe nook is using Adobe Digital Editions under the hood which I've heard there's ways around. ;) I too like having actual books around though, so I know what you mean. that being said, I have a few books that I want to read but it is almost an annoyance that I have to bring the book with me as opposed to my reader when I'm packing light.