Sound? Yeah it has sound (comparable to the powerbook 12" anyway).
Beyond emergency use laptop speakers are never going to sound that good, esp. in a 1" thick package (speaker need volume and air to work). I hardly ever use the speakers anyway.
I doubt the 13" MB has sound which is comparable to a 12" PB. This machine I'm using has so much bass, I've tried a MB and it sound worse than an iBook, a machine I've also owned one time.