I fly this route approximately 3-4 times a year in business class. The SIN-DPS-SIN legs are often very empty in business class (maybe 25% load max) but the flight appears better supported in economy.
I have mixed feelings about the change. I am flying in June on the existing routing via Singapore and then next in September/October. I have checked these flights out and they are showing the A330 which I am not too thrilled about for a 10 hour flight. May have to use another carrier for those flights.
The 787 sounds great from October onwards.