The World Bank's data on a number of development indicators for all countries is now open data. The USA has an Executive Order ( May 2014) to make 'open and machine readable the new default for government information'; and one example is the new open data policy by USAID. The EU has an open data portal and at least five EU countries have portals of their own to help find their open data. Saint Lucia has decided to make government data open data.
Open data has become the new standard. It's different from public information in that the data can both be found and easily accessed. A report published on the web as a PDF file is public information. A published spreadsheet or text file that can be imported relatively easily for analysis would be open data. Governments are the biggest producers and consumers of data - so the operations of government offices should be early beneficiaries of an open data approach.