Well, I look at it this way, all new Boeing and Airbus aircraft are GBAS enabled, with the Dreamliner touting full GBAS certification.
The FAA is basically providing WAAS, so they can get rid of the VOR and NDB's.
Currently, the WAAS program is kinda screwed here in the US. We have the 2 WAAS sats, CRW and CRE, basically west and east. CRW is failing. The single sat over Japan POR, will be repositioned and will be able to cover about 1/3 of the west coast of the US. How this will effect the signal on the East Coast of the US is still being worked on.
Current coverage: Note lack of WAAS coverage in AUS
Here is what the colors on the map relate to:
The POR sat is a single, and provides somewhat of a signal over the northern half of AUS. Due to signal strength, and lack of a second sat, I doubt if you will really ever see WAAS in AUS (unless you want to spent a few Billion to float another sat!)
Here is what the WAAS coverage the US will have with the failure of CRW and adding POR and AMR (new, not yet launched)
update AMR launch has happened and POR has moved, restoring coverage to AK)