Sorry... But it ain't gonna happen. While I would agree that finding hidden easter eggs can be kind of fun and the like, corporate customers would never let it fly. They won't be buying an OS where hidden stuff can pop out and distract users from doing their jobs or possibly be exploitable.
Sadly, I think the days of enterprising individuals putting flight sims in Excel are over, Drew. :-)
With all the planning, testing, and whatnot that is involved it's not good for people to toss in random stuff. ... On second thought, there is always the registry, that's full of features that aren't discoverable via UI.
Lie!!!!!!!!!!!! I found one. There are a lot of new walpapers on the Windows Folder. They are 71231273412835143164273 better than the one that you get in the begin. Search on google. Enjoy!