Since the HTC Arrive on Sprint comes with 'NoDo' built in, we've been obviously testing what has/has not changed. And although we know it has copy/paste, refined Marketplace search and performance enhancements, one other little thing we noticed is fixed: the Marketplace app update bug.
If you recall, we did a video ("Tip: Force an app update in the Windows Phone Marketplace") showing how when a new update is available for an app you have installed, sometimes there's a delay with the Marketplace reflecting that. So you would navigate over to see the new version listed but no way to update it manually. The trick was to hit the back button, then go back to the app description and then you would see the "update" option (just watch the video).
Long story short, 'NoDo' fixes that so the first time you go to the updated application in the Marketplace, it shows "Update", making one less step in the process. Revolutionary? Game shifting? Hardly. But it's attention to the details that matters in making a good OS, so we're glad to see it.