Hugely bizarre - but I just checked back in here to ask EXACTLY the same question. My wife and I get the 7.04 to Victoria from Platform 2 every day - and for the last few weeks the platform has become increasingly busier. I used to be able to walk along and could expect to see not only the same old people on a daily basis, but all of them - inlcuding us, getting pretty much the same train seats - but now I would say a conservative guess is that it is 3 times as busy as it was before and it's not schoold kids either - but adults. However - it's not the overground line, it's the same old train to Victoria every day. I wouldn't say the train itself is busier when it hits Forest Hill, but from Forest HIll onward all the stops seem much busier than the last month or two.