LCD`s havent pushed your cards anymore than a standard Cathode ray tube monitor. if you buy a normal LCD monitor say 19" and under, its perfectly capable of playing at any resolution under 1280X1024, your not locked down to just 1280X1024...
in contrast when cathode ray tubes went SVGA things got interesting as you could have huge resolutions but to see anything properly you usually needed a bigger screen, plus cathode ray tubes have tumbled in price making it very cheap to buy a 19" or 21" as opposed to the relatively expensive cost of an LCD monitor.
i think the better question would be,
"have larger monitor sizes overall, pushed your cards more"
for the most part probably yes but its all down to personal choice. i have a 19" Sharp TFT LCD monitor running on an X800GTO2 modded to X850XTPE and i run most things at 1024X768 with Anti Aliasing and Anisotropic Filtering. its what im used to and its what i like

but if i had a standard CRT 21" monitor i would be tempted to go higher...