I found nothing ambiguous about the final answer. Kevin was quite clear, you can loan a book out ONCE, not once per person or device, but once. Period. End of discussion. He basically said to be happy for that much.
I find it sad that they tried to NOT answer this question and kept quoting the FAQ's ambiguous answer until called out point blank for a clearer meaning. There has been enough talk about this over at the B&N site that the matter would have been cleared up if it wasn't ONCE and ONCE ONLY.
The lending shouldn't even come into consideration when deciding what reader to get, IMHO, at this point. That and $5 will get you a coffee.