It's still early days, but Singapore's approach to fiber deployment is beginning to pay off. In December 2007, Singapore announced a major program to get fiber deployed throughout their city state (see my blog posts here and here). A critical advantage of their approach was government mandated structural separation between the dark fiber layer deployed in the public right-of-way (a natural monopoly) and higher layer services (where competition is possible and highly desirable. To ensure that the dark fiber is lite, they have also contracted with one company to provide wholesale layer 2 services over the dark fiber, but that company is independent of the dark fiber company and cannot prevent any interested 3rd party from directly obtaining dark fiber.
Now three years later, the first stages of the new network are coming on line (it's scheduled to be 60% complete by December 2010). So far there are only(!) five retail ISPs offerring services over the new network. Examples in other cities like Stockholm suggest the availability of dark fiber will result in dozens of service providers (>50 in Stockholm) and very low prices (less than $10/month for 100/100 Mbps service in Stockholm).
This article has detail on the initial service offers in Singapore. The first offer is SG$50 (US $38) per month for 100/100 Mbps Internet access service.
As I've commented in the past, structural separation is critical to obtaining vibrant, but the layer at which the separation occurs is also important. This chart:
provides a clear illustration why the logical layer at which to provide open access (and above which one seeks competition) is dark fiber!