Maybe I'm a wet blanket as well, but I'd rather not have undocumented features if there's even the slightest risk of it introducing bugs or vulnerabilities.
Sadly there isn't much room for Easter Eggs in the modern professional IT industry since software is constantly being attacked (it's hard enough keeping documented features secure!). Which is why these days most Easter Eggs tend to be hidden away online[1][2]
[1] http://konamicodesites.com/ (↑↑↓↓←→←→BA)
[2] https://en.wikipedia.org/wiki/List_of_Google_hoaxes_and_east...