Here's a counterpoint to the currently popular view of "fat controllers are bad", and the current fad of everyone and their cousin implementing service layers: You don't need one. Fat controllers are okay too.

He starts by explaining the "why you don't need a service layer" part, mentioning that keeping it in the controller keeps things simple and keeps your code from having to go through extra hoops just to work correctly. He also points out that, just because he recommends "fat controllers" doesn't mean he's advocating code reuse. In fact, just the opposite:

It's fine if you code your things in the controllers, but there comes a point when you should stop that. The moment you realize you're duplicating your code, stop and refactor. This is one of the very basics of software engineering: Avoid duplication by creating functions and classes.

Now that I am actually using the Zend Framework on my first project, hitting bugs/limitations in Zend_Feed and therefore looking at the code, I must say I am seeing feature duplication with internal PHP features that does not quite fit in with the KISS principle.

He points out a few things that illustrate his point - the use of Zend_Http_Client instead of a strea context, passing XML contents into loadXML instead of just load. As a replacement, he's considered a Feed component from the eZ components system, but it hasn't been released (officially) yet. So, as an alternative, he's come up with a patch to fix a few things in the Zend_Feed component to make it a bit more KISS-friendly.