I think, all in all, I'm pretty happy with the sound features of Second Life. I only hear music when I choose to, and the occasional ambient sounds are a nice touch. However, recently I got to thinking about the idea of having live voice chat capabilities the other day, and... I dunno. I think it might be more harmful than helpful. Consider:

When you read a good book, you supply the character voices, so they are ideal. When you see the movie version, or even see a cartoon version of your favorite story, you're usually bound to be disappointed somewhat; 'that guy doesn't sound like what I thought he should!' And I imagine that this effect would carry over to SL. You're talking with a gorgeous avatar, when you decide to enable voice chat. Suddenly, a new dimension to the flirtation enters the picture, and it can go either way. Don't downplay the power of voice: some people have the aural equivalent of 'a great face for radio'. As shallow as it may sound, an unsexy voice (or accent) can be a deal-breaker.

Let's also consider that many of us are simply more glib and witty when it comes to writing. I myself tend toward mumbling and repeating 'Uhh' when speaking aloud. I'm not saying that everyone does this, but when you've known a person through their visuals for so long, you have, realize it or not, come to expect that their speech patterns are exactly the same as their writing style.

I'd like to be proven wrong about this, but it's occurred so often before that it'll be interesting to see (and hear) what happens when voice chat is finally implemented. Sound off in the comments section!