We've seen recent references to capital being mobile and wealthy people being willing to move elsewhere to save on taxes. We've even read about people giving up U.S. citizenship to save on income taxes.
Co-founder of Facebook, Eduardo Saverin, is an example; see this Bloomberg article for details. Brazilian-born Saverin has given up U.S. citizenship and will reside in Singapore.
See what a strategy of "let's tax the rich" gets you? Our loss is Singapore's gain.