In more words - the expense of maintaining 2 terminals can't be justified. Don't worry, 'Experts' say the half hour it will take for the good folk of south London to get to St Pancras will be saved by the 2 hour journey time to Paris...alternatively, they may even consider going by air in preference to venturing into the north.
If Eurostar continued to a limited service operate from Waterloo even after the full high-speed line to St Pancras is open, it would still have to operate on the same tracks as domestic services in South London.
Although the convenience of travelling from Waterloo will be lost for people south of the river, the trains from St Pancras will still be faster than the present service.
Though of course it will be very odd to catch a train heading south-east from London from a station traditionally associated with services to the north.
In future the other option for SE1-dwellers will be to catch the Jubilee Line to Stratford and pick up Eurostar there.
Does anyone know if all the trains will stop at Stratford?
I personally think it is political correctness gone mad to transfer everything to Kings Cross. What a beautiful place for visitors to see when they first visit London!