It's good as an interface, I think, because the human also requires some startup time -- if you can see what the screen looks like before it is interactive, you can orient yourself while the machine finishes reactivating.
Indeed it's a very good thing, especially if the actual resume can happen in that time span.
Sometimes it's frustrating since it looks like frozen.
Sometimes it's misleading, e.g. when you see that you didn't get an email or a IM notification, and then you realize it's because your e-mail/IM app is not really running yet.
Or when you take a quick glance to the wifi indicator and see that there are many bars and then you go away assuming there is connectivity but when it actually awakes you are not really online.
