Is HttpContext.Items still considered a reasonable place to share things between different parts of a request? Particularly HttpHandler's outside of MVC, like WIF extensibility points.
How do you access this dictionary from within MVC4's ApiController? Without using HttpContext.Current static methods (I still want it unit testable). The normal controller had HttpContextBase/Wrapper which abstracted it a bit for testing.
Use Request.Properties inside the Web API Controller. When implementing an ActionFilterAttribute it's filterContext.Request.Properties
