Looks like Christmas has come early for those Windows Live users who haven't got an @live.com email address yet. PicturePan2, the "unofficial LiveSide correspondent for China" has just posted a new way to register the Windows Live email address of your choice, provided you have Firefox or Opera installed. (You can use the nifty portable Firefox if you don't wish to install another browser.)
Visit Windows Live Custom Domains
Choose "Get Started" then type in a domain of your choice eg "test123.com", and press "Continue"
Choose "Create a new Windows Live ID in your domain" then press "Continue"
In Firefox, go to "View - Page Style - No style"
Now select the @live.com domain from the drop down menu
Important: To be able to receive emails to this account, you must login to mail.live.com with your new email address to activate it
Pictures can be found over at source.
Note1: This could stop working at any time and most likely will do.
Note2: As was stated after the last hack, you risk losing your @live.com email address if you abuse the signup for spam purposes. However it was confirmed that regular users are safe.
It worked for me ... hurry before it's fixed ... reps are welcome
LiveSide - News blog : Windows Live email addresses - Part 3