As from Monday 18th February, there will be 2 direct Inter-City trains per day, on weekdays, between Brussels (Midi) and The Hague (Den Haag HS).
From Monday 11th March, the frequency will be increased to 8 trains per day.
Tickets will cost the same as on the old Benelux train which was abolished in December.
Intermediate stops will be at Brussels Central, Mechelen, Antwerp Central, Roosendaal and Dordrecht - as on the old Benelux.
At weekends, the trains will run between The Hague and Antwerp only.
Direct non-stop IC trains between Antwerp and Roosendaal will continue to run 8 times a day until 11th March.
It is not possible to run direct IC trains between Brussels and Amsterdam because there are not enough free "slots" on the tracks between The Hague and Amsterdam. Even so, journey time between Amsterdam and Brussels should be similar to what it was on the Benelux train.
Inter-City travellers between Brussels and Amsterdam (in either direction) will have to change trains at Rotterdam.
Direct Thalys trains between Brussels and Amsterdam continue as before, of course.
Thanks to ErikdR on the Amsterdam Forum for drawing attention to this.
Links in Dutch