According to this Pycon Atlanta 2010 project page, the Ubuntu One developers are working on porting the Ubuntu One cloud storage service to Windows. This is expected to be open for discussion during the annual Python Conference to be held from the 17-25 of Feb 2010.
The project, which is currently open to participants and volunteers, aims at bringing the personal cloud space that debuted with Ubuntu Karmic last October to Windows. This I believe, will also help prevent a lock-in of the service to the OS (Ubuntu) and open it up to a much wider market. Not to talk about the potential revenue that could be realized by Canonical from the service.
The annual Python Conference is the largest annual gathering for the community using and developing the open-source Python programming language. It is broken into 3 separate parts comprising Tutorial Days, Conference Days and Development Sprints.