Yes, a feature request, but I understand that this would not be easy (so, clearly, I'm not expecting it 'tomorrow').
A web-based front-end that would automate a lot of the signing up for virtal hosting would be a swell thing -- as far as I can tell, the majority of functionality to provide this is already available within web/virtualmin. All that would be needed would be a whois feature, a shopping cart, and payment processing with a recurrent billing module.
This could conceivably be a separate module for virtualmin, to help automate the entire signup procedure for new virtual hosts.
Then again, this might also be a monumnetal undertaking, and my lack of understand belies that :-(