The 457 visa is the primary means for employers to sponsor workers into Australia. The Department of Immigration (DIMA) sets job titles and salary ranges which are eligible for sponsorship, and assigns licenses to companies which allow them to bring in foreign workers. The average 457 visa holder is paid a salary of at least $104,150 which is double the national average wage. This prevents foreign workers being brought in at lower rates than locals and undercutting the marketplace.
Whilst the 457 program is often bashed in the press for supposed abuses these have never been proven. In fact 457 visa holders account for less than 1% of the workforce and even in the areas where Australian IT workers have been vocal about alleged oversupply the actual numbers of foreign workers remain tiny. For example around 5% of the 78,000 software programmers in Australia are on a 457. It has been hugely successful in allowing Australian companies to deal with skills shortages especially within IT where student numbers have halved over the last decade.
Unfortunately immigration has been an easy target for politicians seeking to score points from an uninformed electorate. These continued tweaks to a perfectly functioning program do little more than annoy businesses and put off potential migrants. Recent changes will require employers to have advertised locally to fill any position prior to bringing in a foreign applicant. Despite the unwelcome additional burden on employers, this should not have any dramatic effect on processing times or volumes
If you don't qualify for one of the unlimited sponsorship visas then the 457 is a quick and easy way to get working. Of particular interest to contractors - some Australian Umbrella Companies can sponsor 457 Visas for Contractors - provided that you have a job offer which meets their criteria.