Today we placed our style files for the open.MapQuest.co.uk site up on GitHub. The source is available at http://github.com/MapQuest/MapQuest-Mapnik-Style and is available under the MIT License. There are some changes in there that haven't gone live yet, mainly around adding in the bike and foot paths. We're also working on highlighting the Kibera Project data better than we had originally. If anyone out there has any advice on which key/value pairs to focus on, please let us know at Open@MapQuest.com. Anyway, the style is currently built to work against Mapnik 0.6.1+. It is not directly compatible with Mapnik 2 yet. We were moving so fast that we figured it was best to isolate Cartifact from having a constantly changing renderer during the project, and just run it thru Artem's converter for production. It is a to do item on our list to get it properly converted to Mapnik 2, but as I write I realize it probably gets a wider audience right now if we leave it as is. The style updates are not yet live on open.MapQuest.co.uk, we haven't finished them, but since so much of the feedback since launch has been around tweaks to the style, we figured we'd just get it up now and start the ball rolling! Hopefully I'll be back soon with news of some more changes, enhancements, etc.