I think that it would be a great thing. This tool use p2p technology (the same used by bitcoin and is the technology of the future). But I think that this replacement it would be not never possible. Skype has a tremendous reputation, a big number of people that use it (I think almost all this kind of communication be realized by this tool) and the last but not the less important is owned by Microsoft. Which will not let go so easy this part of market which owns. Then the quality of calls from skype is excellent, they do updates regularly in order to improve their product and, as I know, have no compliant to any type about it. And at the end if Microsoft will see so risks in this competitor will convert in p2p technology its product. With this will be end of story.