[andrewmb]

To provide more of a direct answer, I think that Shenzhen has really great long-term prospects as a tech/innovation hub. Very large number of investors, existing and large tech/innovation/industry cluster (consumer electronics), and long-term government incentives. You can already start to see the momentum building. I've seen major changes since first doing business there (Feb 2012) and even over the past ~2years that I've lived there.

However, the prospects of moving there are not significantly better than the US. China is opening up new classes of visas and making certain business licenses more accessible, but my general impression from being in the ecosystem and talking with locals and foreigners is that it's difficult to get a sustainable business off the ground. The immigration situation (if that is a goal) is bleak.