Actually, by checking “Use the visual editor when writing” option, the default editor will be set to be “wysiwyg” but there’s is no HTML CODE EDITOR any more. It’s really a big problem. some html tag symbols will be reformatted when you click “post” button.
eg.
you type
var book={title:'bookTitle', author:'nate', id:222};
and click “post”
the code you typed will be change to be
var book={title:’bookTitle’, author:’nate’, id:222};
I don’t know why wp’s dev team change the editor worse than version 2.0