One very important factor is the future of print books. Personally I think EBooks will eventually take most but not all of the market assuming small incremental improvements in reader technology rather than a quantum leap, which is of course also quite possible. I think over a generation or more print books will probably contract to a large niche market. (Or, of course, as another poster said, ebooks may reach their peak market penetration tomorrow and stay their or decline. My crystal ball is not infallible). In B&N's case, the trick has got to be managing the decline. To recognise if large stores need to be closed, if they need to be replaced by smaller ones, if they need different product mixes etc. If EBooks are going to dominate, they need to be prospering in that market sometime in the not too distant future to survive in the longer term. Or they need to have an exit plan or diversify. What happened to the carriage makers when cars came along. I'd imagine some folded, some made car bodies, perhaps some of the bigger ones made cars. Perhaps some got into related fields where their expertise was useful. Or maybe they want to be the biggest fish in a much smaller pond. Perhaps a bit of vertical integration can see this come true.
For Kali Yuga, a nice cautionary post, but don't forget the fun. No doubt like others here, my book on how to make a successful small business would probably start with the line "Begin with a very large business". Even if I did have access to their accounts and other information, I don't really pretend to have the expertise to guide B&N through this minefield. Just a nice intellectual exercise based on the little we do know. Perhaps with the odd interjection now and then from someone who really is an expert and the odd one who really is an idiot.