Flash map design because its vector can work as any vector program, flash allowing animation for zoom is a great ability.
But you miss one point regarding maps. A true map is a simplification of the reality, not a photograph of the earth's surface.
Its true if you could zoom in close, you could read the spellbook on the table in the patio of the wizards bachelor pad, but zoom back to 100% and you can't see the building, the town, the river next to it because they disappear in the distance.
A global or regional scale map is generally an exageration of the terrain details - you can see the river in the map, but if you were at the elevation to view the region properly, the river wouldn't be visible.
You don't really want a "map" of the actual ground details at every zoom level. A map is a representation, its not reality.
I think its better to have a global, regional, city-level map, and 1" = 5' scale map for your different "zoom" levels, but these are four different maps, not the same one at 4 levels of zoom. Just my opinion.