[tdmackey]

Google's birthday, I am assuming. Although they tend to flipflop between the 7th and 27th.

[studer]

http://searchengineland.com/google-balls-logo-not-googles-bi... claims to have an official statement:

"Today’s doodle is not related to a birthday but is fast, fun and interactive, just the way we think search should be."

and mentions that there's a Google press conference tomorrow.