We've extended the private-label feature for our Design Partner Program members so they can use a domain name of their choice as the master domain name when creating new sites, before they are mapped to a final domain.
For example, suppose you're a Webvanta design partner using www.joeswebdesign.com for your main site. You can now create new sites for customers at customer.joeswebdesign.com, instead of at customer.webvanta.com, removing one of the last vestiges of the Webvanta name from the private-label flow.
This setup does require that you do some special DNS configuration, which we can guide you through.
When the site is ready to go live, presumably you'll map it to customer-domain.com, but until then (and even afterward) you'll be able to access it as customer.joeswebdesign.com.