My husband and I both got BnN nooks this past Summer and we love them.
The two main reasons that we went with the nooks over the Kindle was that you can add memory chips to the nook, not to the Kindle. The other is that you can replace the rechargeable battery in the nook, not so with the Kindle. (rechargeable batteries can only be recharged a finite number of times)
We also purposely went with the black and white nook rather than the color one because the black and white version is not back lite. You have to have an external light source to read the nook at night. The fact that the screen is not back lite is a good thing as it is much easier on the eyes. I really drug my feet about getting an e-reader to begin with because I look at a computer screen all day long and I really didn't want to look at another one when I was trying to read a book. The type that the nook uses is similar to a very sophisticated etch-a-sketch. On the other hand, the color nook is back lite and therefore also has a shorter battery life between charges.
The other reason that I love the nook is that it is very easy to check e-books out of the library and load them to the nook. You can check them out for up to 21 days. Once the time is up, the e-book is automatically disabled on the nook and "returned" to the library. You do not physically have to take the e-book back to the library. (The best part as I hate the overdue charges!!!) You have the option of "returning" the e-book early by selecting that option when the nook is attached to your computer. Because of the ease of library e-book access, we have not actually purchased very many e-books since we got the nooks.