I'm new to this list, but I had an idea for Zend_form. This is one of my favorite components for ZF, but I feel the biggest most prevalent issue people have with it is the decorators. The one provided is a powerful solution, but I feel it's too complicated. Anyways, I have an example implementation that I think would be easier. Ex:
$form = new Zend_Dojo_Form();
$decorator = "
As you can see, the decorator is just a string, but we can do a regex to simply replace "label" and "element" to be the value provided by the form. I think this is a simpler, more intuitive method as opposed to appending and prepending strings. Also, you would be able to simply use setErrorDecorator, or in a form element simply specify the decorator string you would like to use.
Anyways, just an idea. Any feed back would be appreciated.