Alas, the lines are blurred there too. (pun!) LCD monitors and LCD HDTV's can have the same advantages and disadvantages. There is generally less input lag in computer monitors, though the most laggy computer monitors have more input lag than the "Game Mode" of some of the least-laggy HDTV's. So there's sometimes overlap. In addition, high-priced HDTV's have motion enhancements and local dimming, that computer monitors do not. So the question is not very clear cut.
But there's some generalities. Computer monitors almost always have less input lag -- that's one thing you usually can count on. And there's more computer monitors that can accept a native 120Hz input, than HDTV's that accept a native 120Hz input. The largest computer monitors are 27" to 30". If you're computer gaming, then I'd suggest going for 120Hz, both because of motion blur and also because you get less input lag with 120Hz than 60Hz. And you'll like the reduced motion blur.
You won't get the "sharp motion" of full motion interpolation found in the better HDTV's like the XBR950, but that's usually not desirable for computers, due to input lag, anyway. However, you can gain 120Hz and little input lag. One of the ultimate these days, right now, is the Catleap 2B overclocked monitors from 120hz.net (120Hz native IPS 27 inch, at 2560x1440!). You really need at least a Geforce GTX 680 or similar to drive 1440p@120Hz though -- and that will set you back plenty. 1440p@120Hz is an overclocked resolution, that overclocks both the monitor and the graphics card, so don't buy if you prefer something more widely supported -- then go for 1080p@120Hz from one of the familiar names (Samsung, Asus, Acer, Benq, etc)
Thanks for this detailed info Mark ! Yea, looks like for me, I made the right choice with the TV I got. I've been over happy with it since I got it, and now hearing this just makes me feel like there really couldn't have been a better option at 55" and above. Seriously, my expectations for this TV have been exceeded in every way.
Is there even an LCD HDTV that can input 120hz natively? On a side note, wow! An 120hz capable "IPS" monitor? That's first for me!
Be warned, 2560x1440p @ 120Hz (the IPS 120hz.net Catleap 2B monitor) requires quite the GPU monster -- you'll easily just about break four figures when you buy the monitor and the GPU necessary to run video games at 120fps at that resolution.