A long time ago, I published patch files that would defang the Browse Happy function and remove the “Powered by WordPress” branding from the Meta widget.
It’s rare that WordPress make it easier to simplify things, but as of version 3.6, the Meta hack is no longer necessary. Simply pop this line into any theme or plugin that you’ve written:
add_filter('widget_meta_poweredby', create_function('$a', 'return "";'));