OSWatershed should grab the most popular projects in ohloh's stacks and use that for distro freshness ratings. Its a great way to see what applications people care about. The next logical feature would be recommended a distro based on what applications have the latest versions available for a particular stack. If a script could be written to build an automatic stack (that would be edited later) this system could effectively replace projects like popcon, giving upstream and downstream a better understanding of what people use.