[afv011]

The OP has a point. The automated rooting process replaces some core Android libraries; only the person building those libraries knows what's in them. It is not unreasonable to think that those cooked libraries could cause a problem down the line (think of the Froyo port, which disables battery monitoring). I'm not saying the replacement libraries are faulty in anyway, but the possibility is always there when you replace an official file with one whose origin is unknown.

At the end of the day, it's a personal call. If I were in B&N's position, I would make it clear that rooting voids the warranty, but then, everybody is free to do as they please with their device.