UK's ADF requirement for IFR in CAS is already unusual in Europe, and IMHO this will go. It's completely stupid for enroute.
You will still need an ADF to fly an NDB approach, which may be the case if going to some place with an ILS or a VOR approach and the ILS or VOR are out of service. I've seen several O/S VORs lately in the "deep south" of Europe, and even Tempelhof was down to an NDB approach last year, for quite a while.
I agree the former Eastern Europe is very pro-GA and they may well do the obvious and follow the USA - it's completely logical after all. But they will still need to provide an ILS for all the cheap airlines, so you will find an ILS at any airport that serves the holiday flights, for the foreseeable future.
I can well see places like Brac - a fantastic place to fly to; a model airport which makes most UK ones look silly - getting an LPV approach the day they can.
Looking at the worldwide 737 fleet, I don't see them installing kit for GPS LPV approaches, and getting their company procedures re-approved, when they already have an ILS. If Ryanair wants to fly to XYZ, the airport will ask whether they want the ILS gold plated
