Just a quick article, the London Bus Routes website has finally reported that the Route 137 conversion to New Routemaster will commence on 6th December 2014. It is reported to be a phased conversion instead of a complete overnight conversion and there will be no changes made to the timetable.
It is reported that they will use the last batch of the Euro V engined New Routemaster buses.
So Route 137 is the last New Routemaster Route converted on the year 2014. Next year into 2015 the first route to convert to New Routemasters is Route 55 which is a new contract that Stagecoach London will again operate.
Source
http://londonbusroutes.net/changes.htm