Here's some new images of the new platform 4a at Stratford for the Central Line. The platform is being build as part of the upgrade of Stratford station to handle the Olympic crowds and the extra traffic as the station is now one of the biggest interchanges outside Zone 1 in London.
The Jubilee Line building is in the background here looking towards Canary Wharf.
In the background here is the supports for the new bridge over the railway into Stratford City development and the Olympic Park.
You can see in this image the new station extension building in the background to this shot.