Chelsea/Hackney aka Crossrail 2
There’s a new consultation on this, following last years, and it appears that the Regional option is the preferred one.
The latest consultation will include decisions about the route of the service from Angel, which could be via Hackney Downs/Central or via Dalston. The former includes the potential for a station in Clapton, while the latter has potential for one in Stoke Newington.
More details are at https://consultations.tfl.gov.uk/crossrail/june-2014/