When the announcement hit that Facebook was snapping up WhatsApp (beating out Google in the process), the gargantuan $19 billion price tag was hard to justify. But, with 465 million active users per month, theres a lot of potential for other, perhaps more profitable services. Today at MWC, TechCrunch has heard from WhatsApp CEO Jan Koum that a new service is indeed coming to the platform relatively soon: voice communication.