Simple morphing button concept
Looks pretty clean for me.

the only improvement i suggest, is avoid the animateBack harcode position. Maybe you can save before the animation start, and then, back to the last position.

    containerMove: function() {
        var mO = morphObject;
        mO.overlay.fadeIn();

        startPosition = {
            top: morphObject.top(),
            left: morphObject.left(),
            width: morphObject.width(),
            height: morphObject.height(),
            marginLeft: ....
        };

        mO.container.animate({
            top: 300,
            left: '50%',
            width: 600,
            height: 400,
            marginLeft: -300 
        },
        400, 
        function() {
                mO.content.fadeIn();
                span.fadeIn();
                mO.close();
        });

    },
    animateBack: function() {
        var mO = morphObject;
        mO.container.animate(startPosition);
    }


Also, for my suggestion is a little anoying using a literal object { }, you can use a constructor new function () {} is better for set properties and  handle scopes.