Looks like HTC is going on something of an updating spree. According to reports from multiple HTC users, the Desire HD and Incredible S have both received updates to Android 2.3.5 and HTC Sense 3.0, bringing their software in line with more recent phones like the Sensation and EVO 3D. In addition, the Wildfire S has apparently received an update of its own, and while it's still on Sense 2.1, its Android version has been bumped up to 2.3.5, and it's now sporting the fancy Sense 3.0 lockscreen that we've enjoyed on high-end HTC devices for some time.
To grab the updates on your device, head to Settings > About Phone > Software Updates and tap the button (note that if you're on a carrier-branded device, you may have to wait a little longer before it's rolled out to you). If you've already upgraded, let us know how you're getting on over in the comments.