Restricting Ubuntu One: Due to the beta development phase, there are quite a few functions that don't work. Users cannot sync music files, note tomboy, calendar, contact, files outside of the Ubuntu One folder .
Ubuntu One beta for Windows seems to be quite interesting. A Windows-based cloud service is definitely a good step to diversify the market for Ubuntu Once users. And Ubuntu One could become a potential competitor to Dropbox in the future.
Current Ubuntu One for Windows is well compatible on Windows XP, Windows Vista and Windows 7.
Download Ubuntu One here.