I saw this on London Reconnections and wondered where the idea could possibly have come from. Of all the proposed extensions to the DLR an extension to Forest Hill via Catford seems by far the most ill-conceived. Much of the DLR system is built on pre-existing alignments, and as has been pointed out by others here, a route from Catford to Forest Hill would require an entirely new (and costly) alignment. I think that any extension of the DLR south of Lewisham could be problematic, given that the line is already running at something approaching full capacity. The DLR was designed primarily as a local metro service with frequent stops, and is not ideally suited to longer distance travel. The best opportunity for improved connectivity from Forest Hill is the potential Thameslink metro service, which would provide direct links from stations between Norwood Junction and New Cross Gate to Blackfriars, City Thameslink, Farringdon, St. Pancras International and points north.