Current routes operated by the 777 (77W so far) are: IAD / JFK / BOM / DXB / BAH.
The next routes supposedly coming online with the delivery of further 77W's and 77L's are IAH (77L), MNL (77W from mid January), DEL (77L from March), LHR (77W Jan/Feb), BKK (March?). There was also a plan to convert PEK and PVG from the current Airbus to Boeing operations, although that plan was deferred due to the delay in aircraft deliveries. I wouldn't be surprised if these became 777 routes soon as well.
So the next route to see the 777 in QR colours will be Manila, very soon. The route will be flown by a combination of 777 and A332/333's however, with the 777 only going on certain flights in the short term.
Same will apply to BKK when it starts - two daily flights will continue. One 777 and one A333/332.
Happy New Year everyone.