The brochure is available on the Port of Dover website at:
http://www.doverport.co.uk/_assets/client/images/collateral/Our%20plan%20for%20the%20next%20generation%20T2.pdf
Some salient points:
It states that a 2005 study came up with "The results of the study were conclusive in that no future cross-channel conventional train ferry service could compete with the Channel Tunnel or indeed Dover's ro-ro service."
The brochure goes on to say that there might be some potential for intermodal rail freight services to make a small but valuable contribution to Dover's future operations and that they are protecting the opportunity for a future rail facility should the market require it.
A study with Network Rail estimates that it would cost £5.9m for full reconnection of the Port to the mainline.
I would love to see a reconnection to enable passenger train access to the cruise terminals and that is hopefully not beyond the bounds of possibility. As for train ferries, out of the question. Minor chance of a small intermodal operation some time in the distant future.