The Windows Live Custom Domains team have now released a new Windows Live Custom Domains release update with the following major highlights:

• New UI (user interface) making it easier than ever to navigate around.
• New feature called Open Membership which will allow you to create e-mail accounts in your domain directly from your website.
• Improved error messages and added contextual Help.
• Increased browser support to include Firefox and the upcoming IE7. And soon Mosaic and Opera (these 2 browsers not officially supported).

Via: Windows Live Custom Domains Blog