Here is a list of things I am working on. I work on OpenMapChest in my spare time, so I can't guarantee when these things will be done.
Improving US Address Search
There are minor problems with the address data in OpenStreetMap, such as typos in street names, missing ordinal direction, etc. Most of these problems were caused by data imports that had these problems.
Addresses with these problems aren't currently included in the OpenMapChest maps. I'm working on fixing the problems automatically when possible, and also making the Map Fixer a little easier to use. (Map Fixer is the page that gives a list of data problems that users can help fix, e.g. US Map Fixer.)
Maps for More Countries in Europe
I'm working on completing the European maps, specifically adding more of Europe: i.e. Central Europe, Eastern Europe and the Balkans. My goal is to have a comprehensive set of European maps that can be installed on an SD card with cross-map routing working. e.g. routing from Amsterdam to Athens works.