I still remain convinced that the big change is going to be a unified management system, at least on the back end.
Aer Lingus essentially being a skin on avios.com would seem to be a pretty important first indicator in my mind. I think they will keep the front ends separate (why introduce a new IB card in the US, after all) but fully merge the back end and just have unified redemption rates and status opportunities among all avios programs.