The present perfect passive:
1.) From across Asia, about 190,000 trainees — migrant workers in their late teens to early 30s — now toil in factories and farms in Japan. They have been brought to the country, in theory, to learn technical expertise under an international aid program started by the Japanese government in the 1990s. (Japan Training Program Is Said to Exploit Workers - Published: July 20, 2010, in New York Times.)
2.) A number of the details have been left for regulators to work out, inevitably setting off complicated tangles down the road that could last for years. (Obama Signs Legislation Overhauling Financial Rules: Published: July 21, 2010, in New York Times).
The present perfect for introducing recent news:
1.) For businesses, the government-sponsored trainee program has offered a loophole to hiring foreign workers. (Japan Training Program Is Said to Exploit Workers - Published: July 20, 2010, in New York Times.)
2.) Under pressure by human rights groups and a string of court cases, the Japanese government has begun to address some of the program’s worst abuses. (Japan Training Program Is Said to Exploit Workers - Published: July 20, 2010, in The New York Times.)
The past simple passive:
1.) By 1981, however, clinics outnumbered hospitals, and 15 years later, 90 percent of the abortions in the U.S. were performed at clinics. (The New Abortion Providers, Published: July 12, 2010 in the New York Times).
2.) Godfrey did, and the woman was admitted; she got the care she needed, and in the end she was fine. (The New Abortion Providers, Published: July 12, 2010 in the New York Times).