You can encapsulate routes into modules by splitting the routes into different files and extending the Zend_Controller_Router_Rewrite class. But, what if you want to use the Redirector helper to set a URL based on a registered route?

His method creates the routing instance and overwrites the default getRoute method with a custom one in the extending class.

The issue Derick pointed out:

In PHP 5.3 this would alias the class Interval in the namespace PEAR::Date to the class Interval. For now, this code would work just fine. However, if PHP would introduce a class "Interval" at some point in the future (and PHP can do this as it owns the global namespace) then the above code would suddenly stop working.

Greg's patch makes it possible to "override" the internal class if need be, making it so that code currently working wouldn't break. All it takes is to "use" is like you normally would and and the magic happens behind the scenes.