I just signed up for and configured DK-TV this weekend and it's pretty cool! I used a PC for the browser part and set the DKC-850 for remote live. There should be no problem using a smart-TV to do the same. Just make sure the smart TV you select has a browser function included (some do not).
Watching someone play your piano with full instrumentation in sync with the video could be more than just a novelty. Although the number of On-Demand pre-recorded videos are somewhat limited so far, there is a great mix of recorded live performances, educational piano instruction, and studio recordings as well as some upcoming live performances for the holidays.
I'm thinking of purchasing a small footprint Smart TV so I can watch the DK-TV presentations with the 19" flat-screen TV sitting on my piano.
Yamaha now lets you purchase a month by month subscription which gives you both DK-Radio and TV so you can try it out yourself.
My family is really enjoying it.