Rhodes is not currently supported on Windows 8.0 but will be shortly in upcoming releases early next year.
Are you asking about Big Windows 8 or Windows Phone 8?
I'am very interested in the support of the Big Windows 8. Do you already have a release date for the support of this platform?
RhoMobile Suite v2.2 supports Windows XP and Windows 7 and I think that this support allows to build an application for Windows 8 (desktop).
Thanks for your answer! After our last contact we have build our application for Windows 8 and tested it on a desktop. We have not encountered any problems while building and testing the app.