Well the initial threat of the Jubilee line escalators at London Bridge being switched off till May has not quite turned out as expected - which for once is a good thing. One escalator of the six (two flights of three) is boxed off and being attended too. To cope with the passenger movements the staff have introduced a one way system - up only in the morning rush hour and down only in the evening. If you are travelling in the 'wrong' direction you will have to use the Northern Line entrance/exit or the entrance/exit into Borough High Street.
For once the disruption has been minimal and its working out just fine.