Thanks for posting this, Electric train.
I, too have been very impressed with the genuine commitment and enthusiasm for electrification from Network Rail. Dave Ward, Route Director, Great Western Zone commented on this subject at the TravelWatch SouthWest meeting in Taunton in October 2008, for example - although he also warned that we are looking long term, not just a 'quick fix'. The practical limits are indeed the political will to take it further - and providing the necessary funding.