A Fuji Heavy Industries spokesperson confirmed that the new powerplant is coming, but wouldn't go so far as to say which models would benefit from the new tech. Automotive News reports that other sources claim that the thrifty four-pot will first show up in the Forester both in the U.S. and Japan, paired with a CVT gearbox. The new engine will then begin to crop up in models like the Legacy and Impreza here in the States and the Exiga minivan on Subaru's home turf.
[Source: Automotive News - sub. req.]