Well, I can really speak only for the financial services area, where the private sector is already the dominant actor.
In fact, the general sentiment in financial service circles, particularly microfinance in developing countries, is that the government should play a less active role than it has historically done.
On the other hand, microfinance is a relatively new industry—and it's fair enough to call it that, even for those who are socially motivated and reaching truly poor people. As such, it's going through what you might call a shake-up period in which mistakes are being made, new models are being developed, and there's a lot of learning going on. Part of the learning is about what role government needs to play in regulating microfinance without stifling microfinance.
As I mentioned, particularly in the case of those institutions that accept savings deposits from the public, regulation is absolutely mandatory. But banking regulation, as it's typically done, tends to be problematic for microfinance institutions, which require more latitude to charge higher rates, because it's more expensive to reach the poor, but at the same time not to abuse that right by charging excessive amounts in order to attract profit-seeking investors.