Looks like Air India is all set to launch Shanghai flights via Bangkok from December this year. I remember B747-437B about this sometime back, looks like it is official now.
I was always amazed at the lack of direct connectivity between India and China - considering they share such a long border and have huge populations with tremendous business prospects. The current weekly one fllight of China Eastern Airlines surely does not justify the potential of this route. In addition to this currently Ethiopian Airlines also offers India - China flights (twice a week?).
More info on Shanghai flights here:
An Airbus A310 aircraft will be deployed for the two weekly flights. “There is enough traffic for operations to be viable, both business and leisure,” said the official.
There is already a weekly direct flight by China Eastern Airlines between Delhi and Shanghai. The airline has already announced adding a second flight on this sector. All travel to China other than this has to be routed through hubs like Bangkok, Singapore and Hong Kong