This module has the potential to fill the form theming gap. For now it is still in alpha but it has potential.
It uses jquery to arrange your form elements. Takes into account fieldset (but not the field in the fieldsets).
It does not integrate with the multistep module.
For example we want to add an api key as a variable to our jquery script. In drupal we define our apikey using a settings form. We add the js using drupal_add_js. Notice that the second parameter says 'setting', this is used to tell the drupal javascript system to add the array as a setting in scripts.
About
The blog contains tips for using the Drupal content management system/framework.
Dominique De Cooman is a drupal developer consultant working in Antwerp and Living in Gent. Feel free to contact me to hire me for your projects