Other than VW, I don’t think anyone knows yet if there’ll be a mk8 GTD.
There’s a thread just started over on seatcupra.net on whether or not the forthcoming new Leon will have a powerful diesel engine in its line up. Initial opinions vary from ‘diesel is dead’ to the possibility of a hybrid diesel.
The government do seem to see diesel cars as a bit of a money earner these days, so there could be increased tax implications for diesel car owners / users in future. Also, with the introduction of clean air zones, this could also mean additional penalties being imposed on diesel vehicles, although this would probably be primarily older, ‘dirty’ diesels.