This is still needed. Custom post types sucks badly for wp 3.1.
Sure, its possible to add an archive for the custom post type - but there's no way of adding it to a taxonomy.
A "perfect" permalink structure would be
domain.com/custom-post-type = custom post type archive
domain.com/custom-post-type/taxonomy = taxonomy archives
domain.com/custom-post-type/taxonomy/single-post = single posts
But instead I'd have to use a combination
domain.com/custom-post-type = the custom post type archive
domain.com/custom-post-type/single-post = single posts
domain.com/random/taxonomy = taxonomy archives
So; What Is really needed is being able to configure permalinks for custom post types similar to how they work for the "regular" blog. This should also include making modifications like this:
There's a plugin availible doing about the thing we want, but this should most def be core.
plugin url is http://wordpress.org/extend/plugins/simple-custom-post-type-archives/