The new decreto 616-2010 is valid since 7.7.2010.
The decreto 616-2010 is an administrative order from the President to the migration agency. This is not a law, is a decreto, only the Congress can create a law. The President in this decreto has changed the official policy 180 degrees. Last 10 years the policy was focus on the 5.000.000 illegal from border countries.
a) So now, the new policy is to focus on Non-Mercosur. They were able to manage 3.500.000 people in 10 years, it means they have the resources to deal with 350.000 people a year.
b) The agents have direct orders from the President about how to deal with permanenturist: 1) Reject entrance at the border 2) 30 days ultimatum.
c) The President gave to migration police powers. Now they can double check you don´t have any criminal record in any country through Interpol, they can go to your work to double check that you really work there (contract working visa), if they like they can google you and use your blog to prove that you are working here.
C2) They already have the resources for enforce this because they only need to give you the ultimatum at the border, its a paper and a clear order for the aduanero.
d) Don´t underestimate the efficiency they might have if they want. And about taxes they became extremely efficient, AFIP is increasing collecting at 38% per year. About 15 point over inflation.
http://www.afip.gov.ar/estudios/