I have some good news for you Vernon. I received my Shield yesterday and had the same issue. I managed to find two workarounds:
1. Stream DSTV Now through Chrome (sideloaded). Navigate to
http://now.dstv.com/LiveTv in Chrome. If necessary you can select to use the desktop version of the page. Click on the desired channel -> select open in Chrome and the window will load with a still picture. Click the pause button and then the play button and the stream will start. This method is a bit clunky and after changing channels it stopped working and I needed to clear the cache in Chrome to try more channels.
2. With the DSTV Now app sideloaded. Navigate to
http://now.dstv.com/LiveTv in Chrome. Click on the desired channel -> select open in DSTV Now and through some dark magic the DSTV Now app opens and you can continue to use the entire app as normal while using the right controller as a mouse.
Enjoy...