That statement is true, but meaningless. Never in the history of the H1B visa program has there been any budget allocated to enforcing those regulations. I am not omniscient, but I am only aware of two cases of prevailing-wage enforcement actions over the last 15+ years and they both involved someone making a huge stink because they found out that the job they were denied went to an H1B for a much lower salary.
The common misconception of being under an obligation to work for X number of years for an employer comes from the fact that H1 workers from a handful of countries (India, China, Mexico etc.)
It may be a handful of countries, but what matters is how many visa holders come from those countries. About half of all H1B holders come from India alone.
http://articles.economictimes.indiatimes.com/2011-01-16/news...