There website explains that lending just like that (I just checked). But even if I can only share certain books and just once- that still is a neat feature.
I'm not sure which, if either, I'll get. But I do know that when I compared both before, I had a few things leading me to the Nook. In the following review: http://www.crn.com/retail/220800101;jse ... WATMY32JVN - # 2 is the reason I'm really leaning towards the Nook.
Again, both are good - but I've always been a fan of B&N - so this is probably also a reason I'd lean this way. Another review told me there are way more books available on B&N - but I figure I couldn't read all of them either way - and Amazon has enough books.