There are some amazing organizations working on the 2nd generation of microfinance. One is United Prosperity and their model of Microfinance Loan Guarantees.
The strengths from the article on UP at NextBillion.net

• It doubles the impact of the money invested by socially conscious investors.
• It builds self sufficiency in the local economy by creating formal relationships between MFIs and banks.
• The foreign rate risk is mitigated with this social guarantee model.

Read more at Online Microfinance Loan Guarantees: The Model of United Prosperity | Blog | NextBillion.net | Development through Enterprise.