New content builder prototype code

Main.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content.Pipeline;
using Microsoft.Xna.Framework.Content.Pipeline.Processors;

namespace Pong.Content
{
    public class Main : IContentProject
    {
        public void Run(Builder builder)
        {
            // You can use regex instead of wildcards if you want for selecting files
            // builder.UseRegex = true;

            // Include all .png files with whatever is the default importer / processor
            builder.Include("Textures/*.png");

            // Include tilemap.png with specific importer/processor and settings
            // this will override the above include for any file that passed the wildcard
            builder.Include(
                "tilemap.png",
                new TextureImporter(),
                new TextureProcessor()
                {
                    ColorKeyColor = new Color(1.0f, 0.5f, 0.5f)
                }
            );

            // Exclude the test.png file
            builder.Exclude("Textures/test.png");

            // Include a custom file for a platform
            // and also change its output path
            if (builder.Platform == TargetPlatform.Android)
            {
                builder.Include("touchscreen-android.png", "touchscreen.xnb"); 
            }
            else
            {
                builder.Include("touchscreen-other.png", "touchscreen.xnb"); 
            }

            // Include files and dynamically change their output names
            builder.Include("Platform/*.png", (filePath) => filePath.Replace("replace_me", "something").Replace(".png", ".xnb"));

            // Build the content
            builder.Build();
        }
    }
}