Sun, I believe you basically hit it on the head! (Thanks for the kind words too!)
Depending on the software program and the skill level of the user, it can take hours, days, even weeks to create a map depending on what the originator wants to do with it (b&w vs. color, 3d-ish[shadows/depth], perspective views, amount of interior details[floorplans], etc...).
And these things also depend on if the creator is making exterior landscape (overland?) maps or building floorplans or underground areas[caverns/dungeons].
While rastor programs like Photopaint are great for "adding" final touches and "frosting" to maps, I think using a vector program (cc2, illustrator, coreldraw[my favorite...] is the best way to begin just because you can easily create vector images and manipulate them[move, fill w/color/patterns], add layers to show/hide objects for player/GM map versions not to mention the ease of selecting objects for manipulation (all the doors can be on one layer, walls on another, flooring on another, etc...).
Personally, I think the greatest asset (and downfall) of creating a computer generated map is that you can add so much detail that it becomes too time consuming. You have to know when to stop (or get therapy...). In the end, you have to decide how far you want to 'take' the map - is it a beautiful piece of artwork that's going to eat all your printer ink? Is it a functional piece that is easily understood and self explanatory (for the most part, especially if you make it available for others to D/L), is it both?
Crossby's Kelestia site says this:
"New mapping technology combines full-colour, high-resolution raster, vegetation and relief with precise vectors to show settlements, geographical features, political borders (right down to individual village boundaries), roads, trails, natural and 'unnatural' wonders, landmarks from standing stones to burial mounds and landscape art... and much, much more..."
Now he makes some very nice maps with CDraw 11, but I don't see where the "new mapping technology" is as he seems to be applying a simple plastic plugin effect to achieve the 3d-ish landmass look. But again, that effect is basically the "frosting" put on after the initial vector design work.
Anyway, I think I'm off track enough as it is.....