I just recently started reading about motion resolution, how hard it is to measure, and the possible doubts about how much a test pattern's results might affect real world human perception. However, IF it is important, not only do you want a plasma, you want a Pioneer. And it doesn't even have to be an Elite/Pro, but even a lower line will be better, at least according to three CNET reviewers.
.................................... Moscoviak............... Katzmaier............Panton
Pioneer 5020HD..................900........................1080..... ............1200
Samsung LN46A550.............500........................ 300........ ...........300
Samsung LN52A650.............500........................ 500........ ...........500
Sony 46Z4100....................600.........................500.. .................500
Sony 46W4100...................600.........................500... ................600
Vizio SV470XVT...................700........................700... ................800
Panasonic TH50PZ800U........600.........................600........... ........500
Counting blurry lines: Should CNET test for motion resolution on HDTVs?
While you can see the A550 LCD fared the worst, the other LCDs did just as badly when frame interpolation was disabled. Even the CNET editors mention that they find this tech to be inappropriate for film (24p). Lastly, who knows how much better artifacting has become with FI, but one can be sure that the more motion there is, the higher chances of artifacting.
Food for thought.