var obj1 = { 

    num : 1,

    str : 'foo',

    obj : { less: 'more' }

};

var obj2 = separateObject( obj1 );

function separateObject( obj1 ) {

    var obj2 = Object.create( obj1 );

    for(var prop in obj2) {

        if( typeof obj1[prop] === "object" )

            obj2[prop] = separateObject( obj1[prop] );

        else

            obj2[prop] = obj1[prop];

    }

    return obj2;

}

​

console.log( '[1] obj1:', obj1 );

console.log( '[1] obj2:', obj2 );

for( var prop in obj1 ) console.log( '[1] obj1.hasOwnProperty( ' + prop + ' ): ' + obj1.hasOwnProperty( prop ) );

for( var prop in obj2 ) console.log( '[1] obj2.hasOwnProperty( ' + prop + ' ): ' + obj2.hasOwnProperty( prop ) );

​

obj1.num = 3;

obj1.str = 'bar';

obj1.obj.less = 'less';

​

console.log( '[2] obj1:', obj1 );

console.log( '[2] obj2:', obj2 );