From December, and for the next three years, the full Bedford-Brighton service will go from four trains an hour to two, with two more an hour terminating at Elephant and Castle. No trains will call at London Bridge at all, going via Herne Hill instead, but it's the cut in service that most concerns passenger groups – particularly since the line also serves Gatwick Airport.
If you haven't seen the changes coming to London Bridge, now might be a good time to take a look. From January 2015, Southeastern passengers on the Greenwich line will no longer be able to travel direct to Charing Cross (all trains will go to Cannon Street). Remaining Charing Cross services won't call at London Bridge between January 2015 and August 2016, at which point there's a switch and Cannon Street services won't call at London Bridge until early 2018. There are also disruptions planned for shorter periods for Southern trains.
As if to soften the blow, we were recently shown the new trains that will run on Thameslink from 2016, in preparation for up to 24 trains an hour on the route. You can see a model of the new train at station roadshows in February and March.
Photo by Mark Walton1 from the Londonist Flickr pool