My prediction is that in the next 15 - 20 years, US manufacturing will come back strong. So strong that it will surprise everyone, even me.
It is based on:
http://blogs.wsj.com/chinarealtime/2010/02/22/the-mystery-of-chinas-labor-shortage/+
http://www.economywatch.com/in-the-news/overall-us-wages-stagnant.18-04.htm+
http://www.oil-price.net/Three things are continuing trends coming together to push manufacturing back here...
1. Cost of US labor is declining (stagnant wages diminished by increasing inflation.)
2. Cost of Chinese and Indian labor is increasing.
3. Cost of transoceanic shipping, and inter-modal handling is increasing.
These trends have been consistent for the past 10yrs. The only thing that would upset these trends would be a political upheaval in China that resets their economy.
This makes it advantageous to manufacturer as close to market as possible (China for China, US for US, EU for EU). Much of it will go to Mexico, but a lot will return to US.