Function is a new type?

I was just reading the new improvements in the scripting in unity 3 and i have to say, awesome guys, bravo.


I just didn't got this bit in the what's new section about function now being a valid type. The thing is, i've been using it as a type for a lot of time now, tough i knew it wasn't documented.

So my question is, have i've been using it wrong all this time? Should i go back in time and stop me from doing it? Or it was all right but now it's all right in unity?