Google X was just paying homage to the Mac OS X look and feel. No where can I find an explanation why Google took the page down. It did have a great tag at the bottom of the page that you can still find if you do a Google search for Google X.
"Roses are red. Violets are blue. OS X rocks. Homage to you."
Look at it live! http://www.theplaceforitall.com/googlex/