My favorite change is how configuration has been clarified. For example, see how loaders are configured now - instead of using a giant string delimited by special characters like this:

    'css-loader?modules-true!postcss-loader!sass-loader'

Loaders are configured with an ordered list:

    [
      {
        loader: 'css-loader',
        options: {
          modules: true
        }
      },
      {
        loader: 'postcss-loader'
      },
      {
        loader: 'sass-loader'
      }
    ]

It takes up way more space but it's also entirely clear what's happening.

More config changes are summarized here:

http://javascriptplayground.com/blog/2016/10/moving-to-webpa...