Most of the South East DOO services were done under BR. I was a victim of one of them having been made surplus to requirements at Marylebone (The Thames and Chiltern DOO scheme).
I was farmed out to Willesden (where i can still be found). I work on both the 172s and 378s on the NLL & WLL. I suppose the reason we havent been displaced yet is because of the Olympics and the 7/7 attacks. At the time of the 7/7 attacks the travelling public wanted to see more visable staff, now that viewpoint has changed i think mostly because of costs.
Nobody really knows what is going to happen to us in the long run, the current concession agreement expires in 2014, so i still have a job up to that point. There is also talk that the company are thinking of converting class 172s to Driver open, Guard close as per class 378 operation.
With reagard the extension of DOO the only lines that i can think off that have been done since privitisation is the London Tilbury & Southend now known as c2c, as mentioned the South Eastern HS services and those in Scotland.
DOO on London Overground is on the Watford to Euston DC lines converted to DOO in 1988. The former East London Line with the exception of Highbury & Islington to Shoreditch High Street operated over former DOO schemes the section of the former Metropolitan Line of the East London were converted by London Transport and the section south of New Cross Gate was done under BR. Highbury & Islington to Shoreditch High Street is the only new DOO section of operation.