My first post on this subject was posted on 9th April 2012.
A few snippets:
North Yorkshire Moors Railway
Through services from Pickering to Whitby. Network Rail track used from Goathland to Whitby. New platform at Whitby for use by NYMR trains.
Now linked to Network Rail and through running possible.
Has made it to East Grinstead and through running to Network Rail possible.
Rother Valley Railway
A great deal of development at Robertsbridge and rebuilding of bridges on the line striking out to Tenterden. Short siding connection with Network Rail at Robertsbridge. However no link yet between the Rother Valley Railway and the Kent & East Sussex Railway.
Spa Valley Railway
Opened to Eridge. No physical link to Network Rail
Great Central Railway
The two sections of the railway (Ruddington to Loughborough and Loughborough to Leicester) to be joined once the new bridge over the old Midland Railway at Loughborough is built.
Festiniog Railway and West Highland Railway
New platforms at Porthmadog to simplify through running.