Go look at C#, or any other language that has this concept. The point is not that there would be no nil, anywhere, ever, the point is that you would have to ask for it, and by default, you get a type that can't contain nil.

C# even proves it can be profitably bolted on after the fact (contra pcwalton)... because that's how unobtrusive this change is. It's not like this is a complicated idea, unlike the other suggestions.