I should have been more clear. This is a wealth tax in addition to normal income tax and applies to those who have AR$200million (US$1.5million?) or more, either in this country or abroad.
One wealthy person sued AFIP recently and won the case, but it's now on appeal. This will give hope to others who who are facing enormous new tax bills and will have to cough up on or before 31st March.
If they have any sense I'm sure most of them will already be one step ahead of the tax man. No different from anywhere else in the world.