The Zune HD's onscreen keyboard works in both landscape and portrait views. Here we see it being used for a Web search in landscape mode. You can see the "search with Bing" branding in query box. Also, notice how the letters of the keyboard bulge out when pressed, giving an indication of the key you're pressing while your finger is obscuring it.
In our brief time with a preview unit of the device, we found the keyboard to be just as speedy and precise as the iPhone, but we'll hold our final judgment until we have more time with the final unit.