World Map Generation Ideas #1

Inspired by Voronoi diagrams, especially the usage here.

What I'm thinking of for world generation:

1. Generate a semi-random set of points in the region.  Distribution should be pretty even, so probably start with a hexagonal grid and then perturb each point slightly.
2. Generate the Voronoi diagram of those points.  I need a good library for this, or need to write one.  These regions will define the areas that the player can move between.
3. Generate a random heightmap.  This should use Perlin noise or something to make pretty smooth transitions.  Should also weight by subtracting the distance from the center, or some other metric to give me an island.
4. Determine biomes (desert, forest, plains) based on height and adjacent regions.
5. Generate map features - castles, towns, lakes, rivers, dungeons.  This one is gonna be really complex, and worthy of its own discussion later.