I just received an update notification for my HTC HD7 (sim free) Windows Phone. Microsoft had earlier mentioned that hardware specific updates are on the way and would be pushed soon. Hardware specific updates are basically updates designed for some specific models. Microsoft has not mentioned which are these models. As far as I know the HTC HD7 is one of them. So if you have got a push message for the update let us know your model. If not, try connecting your phone to Zune and check for the update manually by going into settings - updates. If you don't get the update you don't need to worry as your model may not need these update improvements.
According to Microsoft these updates improve battery life, call clarity, or touch responsiveness depending on the model.
The screenshot below shows the version numbers for a number of things after this hardware specific update:
(Update: WMPoweruser.com is reporting that the update is being pushed for HTC 7 Trophy as well on the Vodafone Network)