Perspective is an amazing thing. From my point of view, a major advantage of the Nook is that it does NOT have Amazon behind it. Amazon has been very proprietary about the Kindle, and I am told that you do not have the flexibility in downloading books onto it that you have with the Nook. I have no personal experience with the Kindle, but I know, from having watching my wife, that you can borrow e-books at the library and read them on a Nook. Before buying, check to see if that's true on the Kindle. Free books are generally the best kind.
Also, check to see how many book formats Kindle will support. That's important because books are saved electronically in several different formats. My wife's Nook supports several of them. This can become important if you see something that seems like a real bargain compared to what you might find at Amazon or B&N. My wife found a compendium of classic literature -- more than 80 novels -- for free. It was in a format supported by Nook, so she downloaded it and now is enjoying the pleasures of Charles Dickens, at no cost.
One thing my wife loves about the Nook is the fact that every B&N has a Nook expert on duty. This person has taught her how to use the device and how to download books from lots of places, many of them NOT B&N. They had problems with the power cords on Nooks sold late last year. The B&N person helped her order a free replacement. This is in-store, in-person help, right at the front desk. You can't beat it.
My wife loves the fact that she can read her Nook in sunlight and turn on the backlighting device to read in bed without having any other light source.
Based on her experience an a demo I saw today, I'll be asking Santa for a Nook Tablet. It's a Nook Color with a whole bunch more power, so it can play load the Internet and play Netflix and other videos a lot more quickly than the standard Nook can, and has all the same reader features.
I've tried the Kindle. It's nice enough and it's lighter, but I found the Nook a whole lot easier to read. I liked the page-turning feel of the Nook better, and I think the Nook Tablet has more features.