From the New York Times:
The group’s fortunes have also risen with booming global energy markets, because it unites one of the world’s largest and fastest growing energy consumers, China, with several of the largest producers. The politics of the global energy market have proved a powerful draw to many outsiders as well, from Iran to India and Pakistan, which are attending the meeting as observers. …
The attendance of Iran, which is in a diplomatic confrontation with the United States over suspicions that it is developing nuclear weapons, highlights a predicament for the organization. …
With Iran pressing for membership, Chinese officials and those from other nations have also made clear that they are not ready to consider expanding the organization. But, a “contact group” has been formed to explore observer status for Afghanistan, whose president, Hamid Karzai , was expected to attend the meeting as a special guest. [Full Text]
See also Foreign Ministry’s briefing about SCO summit; Interfax’s Interview with Russian presidential envoy; VOA’s “Rumsfeld Expresses Doubts About Iran’s Role in Shanghai Cooperation Organization”