Howdy,
It is finally here, according to Microsoft Official announcement it looks like with the latest Skype for Windows computer update (download it here) it is possible to make Lync – Skype video calls.
initial testing shows that it is working only between Lync 2013 Mobile & Desktop clients & Skype windows desktop client, testing with Skype iOS and Android did not work, and I don’t use Apple Mac books so here you go