When I got married, I decided I wanted to make maps for my guests, none of whom lived in our small exurb. It turns out this is a pretty common task. I didn't want ugly, low resolution mapquest printout maps though. I wanted to be able to put in points of interest, I wanted a high level of street detail and I wanted some control over the rendering. I was excited to find out about OSM. It turns out, the Open Street Map website allows you to download a section of the map as SVG. Great! However, one problem: it has a pretty small limit on how big it can be, which limits either map size or level of detail. I ended up downloading the entire map, the rendering software and Mapnik style sheets, and having to compile the renderer myself. Then I edited the map in Inkscape, but there are some boundary issues when you just want a small segment of a big map. It was a pretty complicated project, but I think ultimately worth it.
If OSM offered a paid or advertising supported service to help make custom maps, I think it would be pretty popular. I've toyed around with the idea myself of offering this service, but I don't have the time.