I think a modular system is a problem, I know its nice to focus on one task at a time but the biggest problem is when you need to intergrate a task when working on something thats not related to that task.

A better system is to keep all the tools in one main window and to allow focus to the tools you need for the task at hand, I think this helps with workflow instead of jumping back and forth between rooms.

For poser it may not be a bad idea to simplify the interface to allow maximum work space with minimal gadgets and widgets taking up as much room as they do.