wp_list_comments() – need more control

Hi, I’m currently building a new theme where I need a lot of control over how comments display. I need to significantly change the markup by adding wrapping divs, shifting things around, etc. I also need to be able to distinguish between the first and last comment for a post for special css classes.

Is there a way to get more control over wp_list_comments() without having to touch the core? The parameters you can pass don’t help me with what I need to do at all.