We are in the process of migrating the web services we have running on windows in the Amazon cloud over to new servers based on Ubuntu Linux. There shouldn't be any interruption to service as the new servers will silently take over from the old as the dns changes propagate around the web.
Do let us know if you experience any problems though ...
A user kindly pointed out that domain names that contain hyphens were not being backed up correctly. On investigation we noted that Amazon support all sorts of odd characters (in addition to the not-so-odd-hyphen) in domain names and we were not correctly applying the quoting rules that are required in such circumstances.
We have updated the code and rolled out the new version.
Following feedback from our users, we have changed the XML format of the backup files with immediate effect. More information on our support forums
Just a quick update to say that we're investigating a problem where some users are receiving "The specified domain does not exist" errors when trying to access their data. This seems peculiar to only some accounts and we're looking into the cause in more detail.
UPDATE: Have located the bug, the fix will take an hour or two to test and deploy.
RESOLVED: Fix deployed and tested 
We've just made it easier to register for a free account of our SimpleDB backup solution by relaxing the requirement to gather your AWS credentials at the sign up stage. Now you can register for an account but only enter your details when you want to, plus you can purge your credentials from our systems whenever you like - if you prefer after every backup has been completed.
As a side issue, we have fixed a small display bug where an error pertaining to missing credentials was being displayed in the browser as a raw error message rather than being trapped in our code and presented more appropriately.
XML Feeds