Someone in the forums was wishing for the ability to specify a pool of IPs and have them assigned to resellers automatically on creation of the reseller account. Seems like a pretty do-able and generally useful idea.
For reference (though there isn't a lot to say about it) here's the original post:
http://www.virtualmin.com/forums/message-view?message%5fid=13405
Status:
Closed (fixed)