I am not in manufacturing, but I keep seeing how the costs of Chinese labor are almost equal to the cost to build it in the US... Check out this article on the iphone, it would only add $30-40 to make it in the US because Apple would need to import most of the parts... not so much for the labor.
Indeed, costs are increasing in China as the "usual" economic progress continues. Also bigger western buyers require compliance and more and more doing on site audits of factories which all in benefits for the workers in the long term, and which of course in the end increasing cost.
That said, low end products has already left China for Vietnam, Cambodia, Pakistan, India etc basically now since China is too expensive.
And all we consumers cheering for more, better and cheaper...