I agree with Lord Sigma and amplify that passenger rail on the B&A - at least east of Springfield - should be the priority. Think of all the stuff they should / could do: reduce terminal congestion to BOS by giving the B&A line it's own midday layover facilities, pilot a rush hour shuttle from Boston Landing to Mass Ave or Kendall, two ADA platforms through Newton, "indigo" service to Riverside, fare equity between Rapid Transit and zone 1 & 2 in Newton and Waltham, layover facilities for the "indigo service" at Riverside or between Liberty Mutual and Recreation Drive in Weston.
All the consideration so far is for Springfield and beyond. Not many folks will be commuting from Pittsfield to Boston or Chester to Framingham. Nobody else has mentioned Commuter Rail for folks between Worcester and Springfield, which are about an hour travel time apart.