i have the Nook and just love it. Don't worry about the future of BN, it looks like they will be going private at some point. The have made several moves that points them to the fact that the digital ereading is their future with Nook ereader being at the center, Nook Study, Nook apps for Android, iphone, ipod touch and iPad and home computers,
Their library is solid and since it supports epub you can shop pretty much where you want and that includes checking out books from your library. You can't with the Kindle unless you want to do something illeagle.
The Nook's battery life will get you anywhere from 5 to 8 days. It's shorter than the Kindle but it's the tradeoff for have the LCD Screen. And let's face it, finding time to plug in a device after 5 days or so isn't exactly going to ruin your life. besides you can still read it while it's charging.
The nook is already epub so no sending your books to BN via email and sending them back. That's a little annoying. You can just sideload them straight to the Nook
and also you buy books from other sources that are in epub and for some reason you want to try another epub ereader your library comes with you unaltered or any other type of conversion. The kinle is again reformating again and again. Just too much of an unneccary headache to keep on doing that if you ask me.
Nook has replacable battery
Nook and expandable memory
you can finger swipe using the lcd screen (when it goes to sleep) to turn pages. It gives a more natural feel and flow when reading than clicking a button. Though if you like clicking a button you can as well.
Instore support and InStore Experience. Bring your nook in any bn and you get extra coupons, offers, something free from the Starbucks cafe, read any book for an hour. It's pretty fun.
and lets face it much much more stylish accesories