When Microsoft made itswith Windows RT devices available for pre-order a few weeks ago, there was a lot of confusion around the two available video-out adapters, and whether they were utilizing a proprietary connector. But the Surface just uses a standard micro-HDMI port.
Don’t get me wrong. The two available video-out adapters, Surface HD Digital AV Adapter (which is HDMI) and Surface VGA Adapter, are both high quality parts. But they’re also $40 a pop. If you all you need is HDMI connectivity, a simple HDMI-to-micro-HDMI cable, like this one from Amazon, works just fine. And it costs under $5! (Yes, I used this one.)
Secondary display works with Windows RT generally, and with Surface specifically, exactly as it does on Windows 8. You can choose between using PC screen only, duplicate (both screens are identical), extend (both screens are unique and operate at their native resolution), and second screen only.
Somewhat surprisingly, the little Surface was able to drive both its own display and my own huge 27-inch 1920 x 1080 HD display with no worries at all, using the extend mode. (All modes worked just fine.)
Surface internal screen (left) and external screen (right), the latter running at 1920 x 1080
Windows RT (and Surface with Windows RT) also supports Play on Xbox, of course, which allows you to redirect Xbox Store video content back and forth between your device and the Xbox 360 video game console using the SmartGlass app. They also support Play To, a defacto standard for streaming audio and video content to compatible devices.
Overall, the Surface video-story is excellent. Just don’t get suckered into purchasing an expensive adapter you don’t need.