ViewDataForActivation.cs

public class ViewDataForActivation
{
	[Activate]
	public ViewDataDictionary ViewData { get; set; }
}

ViewOutputFormatter.cs

public class ViewOutputFormatter : Microsoft.AspNet.Mvc.OutputFormatter
{
	public ViewOutputFormatter()
	{
		SupportedEncodings.Add(System.Text.Encoding.UTF8);
		SupportedMediaTypes.Add(MediaTypeHeaderValue.Parse("text/html"));
	}

	public override Task WriteResponseBodyAsync(OutputFormatterContext context)
	{
		var activator = (IControllerActivator)context.ActionContext.HttpContext.RequestServices.GetService(typeof(IControllerActivator));
		var forActivation = new ViewDataForActivation();
		activator.Activate(forActivation, context.ActionContext);
		var viewData = forActivation.ViewData;
		viewData.Model = context.Object;
		var result = new ViewResult();
		result.ViewData = viewData;
		return result.ExecuteResultAsync(context.ActionContext);
	}
}