Everyone hailed the Nook as smart business. Now, thanks to the very same company that powers the Nook, it’s going the way of disco -- fun while it lasted, but an impractical long term way to groove.The hype around Google’s new Nexus 7 tablet is mostly surrounding its threat to Amazon, and while there may be merit there, the striking first casualty is Barnes & Noble. With brick and mortar bookstores and physical reading of books declining in favor of e-readers, Barnes & Noble....