I don't know if that parcel is viable anymore given the Trilogy development next door and future plans for the area. That plot of land is one of the last areas in Boston ripe for development and I think there are big plans for it.
If and when they tear down Fenway (hopefully much later rather than sooner) they should move the park to the South Boston waterfront and use it as an excuse to improve public transit to the area and spur development.
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=fenway+boston&sll=39.953186,-75.174967&sspn=0.289498,0.518417&ie=UTF8&hq=&hnear=Fenway,+Boston,+Massachusetts&ll=42.343875,-71.041739&spn=0.008723,0.016201&t=h&z=16