ZE2 nested classes question

Question about a change coming in PHP 5 / ZendEngine2 : I'm not clear on exactly why you would want to nest class definitions, especially if the proposed change to namespace handling goes away - i.e. you still have to do $this->otherclassfunc() inside a class function, instead of just otherclassfunc(). What is the difference between class Foo { class Bar() { ... } ... } and class Foo { ... } class Bar { ... } ?? In the Foo::Bar() example (the first one), it's not like Foo::Bar() inherits anything from Foo. You still have to explicitly say that Bar extends Foo for that to happen. Thanks