Even if some insane insomniac de-twiddles the pages upon pages of optimized indirection in this code (which I seriously doubt), all Skype has to do is tweak the protocol or encryption and the researcher is back to square one. It's a losing battle. And that's not even getting into the legality of it it all.
How about instead of trying to fruitlessly crack Skype, we spend the time making something that's both open and better?
Concerning the open and better issue; There definitely are open alternatives. None of them have quite the firewall-defying capabilities of Skype. Nor the user base for that matter. Building any kind of social network is fraught with chicken&egg problems and those first to reach mass have it made. Just check how one of the richest and most powerful technology companies Google is struggling to get a foot in Facebook's market.
There's value in making an open client that works with the existing network (for example, Microsoft recently killed the Skype integration plug-in for Asterix).