Mapnik ... success!

Here's how I imported, rendered, and served OSM data through mapnik, locally:

1. Do all downloads/installs ... python (2.5 worked for me), postgres/postgis (8.3 worked), osm2pgsql, mapnik, rendering/mapnik utilities for OSM
2. Follow info below on osm2pgsql
3. Make sure mapnik bindings are registered with Python, run the demo under demo\python to make sure mapnik works, here are pretty good instructions from the OSM wiki
4. Follow this readme to run generate_xml.py and generate_tiles.py. Use my tips below if you get stuck ... also make sure you keep your coordinates straight ... these scripts won't throw an error, they'll just crash
5. Once you've generated tiles stick them in a web accessible location and use this tutorial to get them working with OpenLayers ... note the "bespoke" section, which shows how to add your custom tiles

... now to customize the rendering I only need to modify the map.xml file created by generate_xml.py ... I could do this manually or might look into the qgis plugin ... also cascadenik looks cool