MK,
Thanks for sharing this and it is a very useful info indeed.
I think this article actually answered your earlier question already re: compensation of expat or rotating employees. That is, expats are employees of the parent company sending them to the US and not that of the US entity and hence, their pays are borne by their parent companies.
On a personal side, I find the arguments of American employees suing their employers in this issue a bit "over kill" and I'm glad that US courts did not agree with them. Otherwise, what would happen to expats in Japan? Will they also sue their companies here for not speaking English?
Just my two cents....
Regards,
Jun