Project lead of Zend Framework development Matthew Weier O'Phinney, introduced new MVC interfaces proposal about a month ago. There were a very active discussion about those changes that should be applied to MVC stack in order to produce new quality solution for ZF 2.0
General ideas within this proposal are:
make MVC standardised and easy understandable
allow to create custom MVC layers
provide simple native MVC implementation
And note that the main point is to provide Interfaces for each component that will allow to extend and replace them with an alternative implementations that will implement the appropriate unified MVC component interface.