As of today, ccm <https://github.com/pcmanus/ccm>supports Windows. It should work in both cygwin and the general command-prompt though there are some known issues right now which are documented in the README.
If any Windows users are so inclined to test or tinker I'd be happy to field questions / concerns / fix bugs; feel free to email me directly about it. -- Joshua McKenzie DataStax -- The Apache Cassandra Company
