David,
Currently Microsoft Office Live Workspace is specified/controlled by a single Email address which is taken as the Windows Live ID for that account. You can add multiple users as Editors and Viewers to the documents but you cannot change or transfer the account administrator to any other email address.
If you tried to change the Windows Live ID of your Microsoft Office Live Workspace account, it will break your account and you won't be able to access your existing documents.
Thanks
Sunil Raina
Microsoft Support Engineer