A:Answer Yes you are able to use your ROKU, simply plug your HDMI cable into the back of the TV that is connected to your ROKU device then switch to that HDMI port using your remote and stream away on your Roku device as usual. No, FIRE TV is not replacing ROKU. ROKU is a leader in streaming devices as well as smart TVs with Roku built in, they're even making their own TVs now. ROKU, AMAZON'S FIRE TVS and now GOOGLE are all available for purchase. Hope this helps you make a more informed buying decision.