And the notification came today:
Advancing the date of conversion of 12278/12277(Puri-HWH-Puri) Duronto Exp. to Shatabdi Exp. from 02.04.2013 to 08.02.2013 and exemption from payment of defferential fare to already booked passengers of this train from 08.02.2013 to 02.04.2013.