SriLankan joined today.
I had a look at their route map and noticed that they have plenty of codeshares with non-OW airlines (Etihad, AlItalia, Oman, Siberian, ....)
As a warning to fellow members of this forum I just wanted to let you know that you should use caution when booking any of these flights if you want to collect miles.
Flights must be marketed and operated by a OW partner in order to collect miles.