Poly9's product "Poly9 Globe" is self-described as a "cross-browser, cross-platform 3D globe which does not require any download." I suspect it is more of a presentation tool, though, and thus would improve on the maps currently in iMovie (which lack Great Circle animations between places!).
Still, who knows what it might turn into when connected to Placebase, the other mapping company Apple has bought recently (though neither seems to have direct access to a repository of high resolution imagery, such as what Google and Microsoft have). I'll bet on one thing, though: Whatever comes out of this acquisition, it won't require Flash to run:-)
One more thought: The more 3D globes the merrier — Google Earth and 3D Google Maps have been at it all alone in the mainstream web mapping space ever since Microsoft abandoned its 3D virtual globe in the latest iteration of Bing Maps.