I tend to doze off while listening to music / audiobooks / podcasts in bed. Then, I would remember to shut it down the next day. I normally do this with my iPod but this could be a good alternative.
I always wanted an app which would play audio files and then, shut down after sometime (like I do). I found this app which reduces the sound volume of your computer in a given amount of time and speed and then shuts down your computer. Awesome huh?