If you haven’t already then go check out and read the proposal made by Weston. When I first saw this I nearly peed my pants from joy. It was that amazing. Being able to see the widgets live is going to be a huge thing. Not just for theme developers but for plugin developers as well.
One of the things I’m really looking forward to is being able to see how any widget will look like rather than having to have a separate tab open and then refreshing it. Yeah. That’s how preview widgets. That was until I came across the plugin. See it in action:
Now, as you can see at the moment it does have a few things that may need a little polishing but that’s okay.
Now, the one thing to keep in mind is that you may have to add a line of PHP in your theme’s functions file. Easy really. Just one:
add_theme_support( 'widget-customizer' );
And boom! Now your theme is able to create live widget previews.