> Right now, use Skype. But it will not hold the market when more robust, flexible, decentralised, transparent services are ready for non-technical users.
You forgot "easy to use", "fun" and "attractive". Normal people don't care about those things you said.
All three criteria you mention are very easy to meet. Skype's GUI was thrown together quickly in Delphi. Yet it's good enough for most users. The bar is set very low.
Features could be added to a next generation "open Skype" (e.g. streaming music or video to several of your friends, simultaneously) that would make it even more fun and attractive, but the RIAA and MPAA would be up in arms within 24 hrs of release.
HN is a place where we routinely discuss things that "normal people" don't care about. That doesn't mean those things are not important. Someone has to deal with the details that enable you to make your easy, fun and free calls, though you might not care such details.
You forgot "easy to use", "fun" and "attractive". Normal people don't care about those things you said.