Enjoy the silence.
There are basic features that will be built in to the Integrated Voice feature such as being able to ignore individual players' voices. But the most important thing to remember is that the feature is optional. Just as the quality of online play varies with the people with whom you are playing, so does the quality of online voice vary with the people to whom you choose to listen. We all hope for pleasant voices from informed minds, but what we usually get ranges from the comedic to the downright scary, as illustrated here.
Another forum thread (unfortunately, now deleted) suggested that no one was going to use integrated voice and that it was a waste of development resources. A different player asked "What do you think Blizzard is made up of? One guy named Bill Izzard who has to do everything?" Drysc responded with
Bill's a nice guy, but you're right, we also have Bly Zizzard. So, yeah, two people who do everything. But really I don't think it's important to justify our development pipelines, or explain that a programmer is different from an artist, or UI designer, or web designer. If you don't want to use the voice chat feature you'll be able to disable it.