In the demo's frontend, explore how a Magento-driven store might look to your customer and test some of the features. Get a feel for it by going through the checkout process, tagging a product or leaving a review.
Recently I've been helping a few folks migrate websites from WordPress to Drupal. Presently this works for migrating to Drupal 5 so if you want a Drupal 6 site first migrate to Drupal 5 and then upgrade the site to Drupal 6.