I don't think there is a blackberry os to use in a vm. Do you mean you're trying to setup Blackberry DM in a w2k VM so that you can "see" your blackberry and save your phone's data, upgrade it's os, etc??? I'd love to do this as well, but the usb issues in Parallels seems to be the main stumbling block. Second, linux doesn't have a driver for the blackberry so it can't pass through to the VM. I do understand that the mac os does have a driver that works.
I have been using my BB on Parallels for some time now. What BB do you have and so forth. I think we may be able to help you out ;-)
I can get my blackberry recognized please give us a little more info regarding your BB/ Desk Top manager etc so we can help you!