I've logged an issue about this in GitHub.
I've confirmed that my Laravel environment is set to local, but the asset pipeline still concatenates all of my assets into my two application.js and application.css files.
Has anyone else run into this in Laravel 4.2?
To fix this, I needed to remove local from the concat setting in the codesleeve config file.
'concat' => array('production', 'local'),
should be
'concat' => array('production'),
I think most developers would, by default, prefer not to concatenate files in development mode, which is I think where the confusion came from.