Corbin added support for custom date and time formats in the screensaver.
You can use that to give the date and time the format you want, or you can remove them and get a clean screensaver which only shows the background.. or you can write whatever you want in there (for instance: “KIDS: DON’T TOUCH MY COMPUTER!!”) :)
I guess you could already do that with the away message.. ah well, more customization :)
Note: Joseph is working on adding “background slideshows” to Cinnamon. That should also impact cinnamon-screensaver when it’s ready.