It is not the same speed in every country, because it depends on productivity increases. If a country provides the legal framework to make investments attractive - property rights, not too much corruption - I don't see a reason why it should not reach ~half of the level of the productivity in developed countries.
For China in maximum 50 years the wages should be at least half of western European ones. Full wage equalisation may not come, because physical proximity to those who own more capital may boost wages a bit, but currently the differences are much bigger than that.
In Eastern Europe adaption to western Europe living standards is something like 1-2% per year (was so for Spain, Greece, Portugal after they joined the EU), starting from 30% or so in case of Poland. Again, I expect some gap will remain for a long time, but your oursourcing project should make profit taking such equalisation into account - of course outsourcing is one of the main reason for the wage equalisation.

There may be some jobs, such as currently hedgefund managers, who got wages up to a billion $ per year. But I think we have seen a peak for a long time in financial engineering payment, and at some point I guess, the financial industy will diversify as well a bit more around the globe, leading to both, more competition in this area and if this uberwages remain, they will be at least diversified.

Gemach, gemach