I am told that there are two major (only?) ISP in China - China Telecom (CT) and China Unicom (CU) - and that traffic routed between the two is really slow, almost as bad as traffic that has to cross the Great Firewall. To work around this problem, you (as a web site operator in China) are supposed to get two external IP addresses for your web site, one for each provider.
Feel free to comment on if that is really necessary, but if it is, how would one implement the proper routing for this? Put both IP addresses into DNS for the same host name and let the client somehow figure out which one is better? Separate host names?