I think it's increasingly outdated on laptops, and good riddance too. It was never introduced because it was technically better, it was simply price and economies of scale due to the HDTV connection you mentioned. Plus of course the marketing advantage as you could label them with the same "High Definition" monikers that were used on TVs at the time (never mind the fact that the resolution had actually dropped from 1920x1200 to 1920x1080 in many cases).
We've then had 10 years of laptops with uncomfortable screens and whopping, fat bezels at the bottom of the screen, but then 16:10 and 3:2 display have started to trickle back in - especially in "hip" devices like the Surfaces. Thinner bezels have become increasingly cool to have, the marketing label "HD" no longer sounds impressive, and companies are waking up to the fact that 16:9 displays are increasingly perceived as being old-fashioned now.
And like I say, I'm OK with it. What I now want to see if a resurgence of 16:10 monitors, and hopefully some 3:2 ones as well. However this may take a bit longer unfortunately.