I think German is an incredibly useful langauge for business after English because it is the most popular second language in Europe - the EU is becoming richer and richer and is already a major player in world affairs both politically and economically. Secondly, Germany is the world's 3rd richest country (after USA and Japan) and the largest exporter of products (almost caught up by China though :P) and so has great business potential.

I disagree that French is a useful business language as most the countries that speak it are very poor. Only France is rich (and Canada but they also speak English).

I don't think it is Chinese YET. But it probably will be one day. :)