Microsoft is yet to announce a date for Windows Phone 7 "Mango" to start rolling out to devices, but it looks like it's going to be very soon.
Vodafone Australia just updated their "device software update" page, and in that update comes a goodie:
Testing for Windows Phone “Mango” firmware update has been completed and approved. Awaiting deployment from Microsoft
The build number is now the RTM build, "7.10.7720.68" and requires the previously public NoDo build "7.0.7392.0" to update.
The device in question is the HTC Trophy, and the post gives no details as to when. It's suspected Microsoft will announce the update at their BUILD conference this week, however there don't appear to be any sessions related to this, just development for the platform. If previous indications are correct, Vodafone global as a whole approves the updates, so this should mean that it's approved worldwide for deployment on that network.
Either way, this news means that Microsoft is close, and is attempting to get most carriers onboard before flipping the switch.