Further, ILS at the principal U.S. airline airports will remain primary. As well as in the lofty ICAO world.
Well the intent (both FAA and ICAO) is to eventually replace the majority of ILS installations with WAAS or GBAS approaches (i.e., LPV and GLS). GLS CAT I is already operational in the US, and the FAA is currently testing GLS CAT III prototypes. (Only about 100 of the 1,200 ILS systems in the US are CAT II/III).
The FAA had planned to start phasing out some ILS installations by 2015, however the timing may be under review.
I believe the FAA is still committed to decommission the vast majority of VORs by 2020. A huge number of existing ILS procedures must be revised as a result. I wouldn't be surprised if many of the ILS procedures will be retired along with the VORs.