China. China are trying to put the brakes on their economy and slow it down right now... think how much it would be growing if they weren't applying the brakes. It's different to the Industrial Revolution of 100 years because of the access to knowledge and IT they have access to these days that we didn't have for the Industrial Revolution - the access to knowledge and IT they have allows them greater productivity and efficiency than what was possible in the 18th century. This is why they can grow at unprecedented rates never seen before.
China are urbanizing their population. This requires investment in infrastructure... they invest around ~7% of their GDP in infrastructure. Even if their exports slow, they will still continue to invest in infrastructure as you can't move people from rural areas into cities without infrastructure.
China will not rely on their cheap manufacturing forever... they will eventually move away from manufacturing into services and other areas. The manufacturing will then shift to other parts of the globe where it's cheaper, this is all part of globalization. A shift from manufacturing doesn't mean the end of China, it's a good thing and part of the process.
People have been betting against China for the past 20 years and gotten it wrong, they will continue to bet against it today and into the future and keep getting it wrong.
Who are you going to bet on? The developed economies in the world who are basically bankrupt, or a Government who saves an incredible ~35% of their GDP and is the world's largest creditors? I know where I'd rather put my money.