If you look at this area you find that development halts after about a year. Updates may happen to fix big things like a Netflix change but that's done by Netflix, not Samsung.
Sometimes a patent case wipes out a feature. That recent one about program guide killed off that app in Sony and Samsung.
This is partly why I don't worry about the Smart part of these models. I'll get a Roku or other and that seems current and cheap to replace.
The other big problem is something call Samsung PIA. Not happy so my first step is to shut down the Smart part.
There are some really good deals on the 2014 DSamsun H6400 3D TVs but I note than Samsung have moved to Tizen os on their newest systems. If I buy one of these TVs am I going to find myself with very few apps in 3 - 4 years time? There is nothing in the price range for the new model 48" tvs.