I read Mary Jo's post that T-Mobile USA was rolling out an HD7 update. I am roaming on GCI in Ketchikan, Alaska and never received a notification, but plugged my HD7 into my laptop, started up Zune Desktop, and found that an update WAS available. However, that update was just the pre-NoDo update so NOTHING has yet changed on the device.
The update wizard showed that there were 9 steps to go through and the first six flew by in seconds after which my HD7 rebooted and hung on Step 7 for a while. At the end of Step 7 it rebooted again and moved into Step 8. I then saw my customized Start screen reappear as the update process then moved quickly through Step 9 and was done with a successful update message. You can check out this T-Mobile forum with screenshots of the update process if you are interested.
I never backed up anything and just went right ahead with the update and was a bit worried that I should have at least written down all the apps I had loaded since the recovery process on Windows Phone 7 is not setup like Android where you can easily see all the apps you installed. That worry wasn't warranted though as everything came back as it was jut before the update.
I have to say it was one of the smoothest updates I have ever experienced and it was likely just created to test the system out. So to be clear, this update will take your HD7 to software version 7.0 (7008) and is NOT the NoDo update. That was a lame Tweet by T-Mobile USA to get us all excited for nothing, but maybe NoDo will follow shortly.
Mary Jo actually said that people on Twitter stated NoDo followed shortly so I will keep refreshing the Update option on the Zune Desktop to see if it comes my way too.