The Windows Live Custom Domains team has a post on their blog entitled Bye bye beta….Custom Domains v1 has launched which states

We’re leaving the “Beta tag” blanket at home.  That’s right…thanks to your beta testing and feedback; we’ve now officially launched Windows Live Custom Domains.  Our colleagues over in Messenger kicked off the Windows Live launch season last week.  Along with the launch of OneCare and Live Favorites, we're excited to continue the momentum.  Windows Live is about the Web, the way you want it.  Personalization is a key piece here, and let's face it...your identity online is central to that.  Custom Domains enables people to use all of the Windows Live and MSN services they want with an ID that's as unique to them as they want it to be.

For those who aren’t familiar with Custom Domains, we provide free hosted e-mail for your domain.  Let’s say you own the domain name, “wingtiptoys.com.”   With Custom Domains, you get unlimited, free e-mail accounts at that domain.  You can open accounts for sales@wingtiptoys.com, owner@wingtiptoys.com, etc.  Oh wait, did we mention that it’s free?  This isn’t one of those “free during beta” trial offers.  This is free for life. 

New Feature: Open Membership

We’re jazzed about a new feature we’ve added called Open Membership.  How does this work?  Let’s say you run a website called “soccerfan.com.”  Your users love your site and want an e-mail address @soccerfan.com.  Prior to this launch, each user would have to request an e-mail account from the administrator.  Then, the admin would manually approve and create each account.  We’ve made things much easier all around with this launch...With the Open Membership featured enabled, we provide URL links so users can automatically sign-up for an e-mail account @soccerfan.com.  Admins no longer have to burden with the manual creation of email accounts, and users get accounts immediately.

Congratulations to the team, it's good to see more Windows Live services coming out of beta. I really like this service but I'd love to see it expand to cover other Windows Live properties. For example, will I be able to ever use my own custom domain for my Windows Live Space?