Just for closure on the topic, in case anyone reads this thread in the future, looking for solutions: I did finally get the Poser 8 preview to antialias properly.  It looks like the key was checking the OpenGL Support box on the OpenGL tab, under Compatibility, with nHancer.  I also let Vista run all its requested updates and updated my nVidia drivers again, but neither of these seems to have been what fixed matters.

Checking the OpenGL Support 2 box breaks the effect.  Thus far, I've noted no problems from using nHancer.

So, anyone who's having trouble in the future, it may help to try nHancer.

Thanks again for the help, folks!

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Cage can be an opinionated jerk who posts without thinking.  He apologizes for this.  He's honestly not trying to be a turkeyhead.

Cage had some freebies, compatible with Poser 11 and below.  His Python scripts were saved at archive.org, along with the rest of the Morphography site, where they were hosted.