As I have said previously, the US Dollar DX index may be less useful now because of its almost quaint concentration in the Euro, Yen and Pound, and lack of representation in the currencies of the high growth countries of the emerging markets, particularly India, Brazil, Russia and China.
The Anglo-American banking cartel would like to keep it that way as well. Encouraging the western central banks to inflate their currencies will maintain the appearance of stability while monetization and even devaluations can occur.
Still it is nice to have some historical context.