I'd definitely like to see MH join ST. Good product, decent connections to USA, decent coverage of SE Asia. Plus, those FAs are just... well... up there with Singapore Boys.
I don't see China Eastern joining SkyTeam, certainly not if either SQ or CX becomes a major investor. More likely, MU goes to oneworld. Air China is already in *. CZ is already in ST. It just makes sense for MU to wind up in oneworld, as the three major mainland carriers would be paired off with each of the three major alliances.