Can't send from iCloud.com address which was a me.com address?

So the lasted iOS seed wanted to upgrade my @me.com address to iCloud which I'm fine with, I prefer it in fact.

However, I can't send from a name@icloud.com address. When I sign into iCloud.com/AppleID Managment/Mountain Lion/iTunes, my name@icloud.com address reverts to my old name@me.com address.

In which case, what is the point in this icloud alias? I would like to send mail from the icloud domain instead of me.com. Anyone got it working?