Classic Nook and audio playback
When I bring albums from my iTunes library to the nook they maintain the track order. I really enjoy the fact that I can read and listen to tunes with one comfortable device. Yes the nook is enormous as an mp3 player, but I use my nook cover as a wallet and it works out great.
I was disappointed the new wifi nook has no audio player.
As far as audio quality goes I have to say that the nook sounds great. I have an iPhone 4 and the sound quality is to my ears harsh compared to the nook. I mostly listen to classical music and installed an 8gb microSD card into my nook so I could access more music.
Until I installed 1.7 I had some problems getting the nook to recognize the microSD card. There are some funny things with audio and the nook though. Occassionally I get drop-outs, and when I press play after the nook has been off for a while, audio doesn't always output. I have to either insert the headphone jack a bunch of times, or let the sound output via the speaker before I can hear music.
All of that taken into consideration I still love the nook. It makes my commute to and from work (bus/train/subway) much less stressful and I always have something to read.