That's definitely overstating it. They are better than everyone else in the consumer space. Not enough to be worth 8.5 billion for but the core underlying technology is good(They suck at client development though). People underestimate how hard VOIP is because it sounds so simple.
The echo cancellation algorithms, the speed of their sip like algorithm as well as the infrastructure to run their entire network is an engineering marvel. While, Skype's UI could use an update as well as some usability testing, their backend infrastructure is most definitely not a POS.