Yes, there is a new railway line cutting through kent. It's the high speed channel tunnel rail link. The first stage is up and running with Paris/Brussels to London Eurostar trains wisking along at a cool 300KPH!!! Commuter services along the line will hopefull be available along the line after 2007 when the 2nd section is complete, stopping at Folkestone, Ashford and a possible extension to Dover, plus Ebbsfleet near Gravesend, Stratford before finally reaching St Pancras. The line doesn't just benefit "Cockneys" there is an International station currently in Ashford, kent.
there's plenty of info at ctrl.co.uk