These methods were removed after the 0.4 release because:

1) popups are opened/closed by calling dijit.popup.open()/close()

2) StackContainer widgets (TabContainer, AccordionContainer) use a transition() method to switch between two widgets (for example, you might do chained animation, fading out one widget before wiping in the second)

3) You can make an arbitrary animation to show/hide a widget using the dojo.fx code (slideIn, fadeIn, or something more complicated using animateProperty and/or combined animations on myWidget.domNode