I've been in touch with TfL again over the opening date of Shepherd's Bush station. Their reply:
The responsibility for delivery of the new West London Line station at Shepherd's Bush rests with Westfield, the developers of the adjacent White City shopping centre. We understand that Westfield is expecting to have the station delivered to the appropriate standards and ready for service by the end of the year. Transport for London (TfL) will then take responsibility for operating the station as part of the new London Overground network."End of the year"? That's very nearly a concrete date.
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