I have been following up the growth trajectory of both countries and I can say barring any last minute hiccups (which happen quite frequently) India will start decreasing the margin in next 15 years and in next 40 years India will pull ahead of China, at least in PPP figures. Then again that was prediction basis China population increasing to close to 1.45 billion and then reducing back to 90+crore population and again slight increase in population to 1.16 billion by 2060-80 probably. New data gives the figure around 70 crore population for China and 1.20 billion for India. If this new data is correct prediction then China growth is going to have a bumpy ride. My personal observation though.
Alright Alright, if any of you live up to 2100 , you can check the video for its veracity. Till then bask in imagined glory.