Y is no new logo for cinco de mayo?

I noticed the same thing, wow, that's pretty fucked up on Google's part. Ouch. I appologize mexican and latino community, for Google's political incorrectness =]

Google "Google Cinco de Mayo" and you'll see they've never done it

If Google have never done a "Cinco de Mayo" I wonder if Google care for the mexican community in the US.
FYI. This is a mexican festivity for mexicans in the US exclusively, not all latinos and not all mexicans outside US.
I Still think Google careless for this community.

Google is rolling out a visual refresh that includes a new colorful logo. It would be silly to show a doodle instead of the new logo.

http://googleblog.blogspot.com/2010/05/spring-metamorphosis-googles-new-look.html

Another explanation could be that Cinco de Mayo is a strange holiday that's not even celebrated in Mexico.

"Cinco de Mayo (Spanish for "fifth of May") is a voluntarily-observed holiday that commemorates the Mexican army's unlikely victory over French forces at the Battle of Puebla on May 5, 1862, under the leadership of General Ignacio Zaragoza Seguín. It is celebrated primarily in the state of Puebla and in the United States. While Cinco de Mayo has limited significance nationwide in Mexico, the date is observed in the United States and other locations around the world as a celebration of Mexican heritage and pride." (http://en.wikipedia.org/wiki/Cinco_de_Mayo)

“It has been vastly commercialized on the [US] side of the border,” says Oscar Casares, who authored the novel “Amigoland” and teaches creative writing at the University of Texas at Austin. “They created this mythology of what it means to Mexicans when it is really a minor [holiday]. It is acknowledged but it certainly is not celebrated.” (http://www.csmonitor.com/World/Americas/2010/0505/Bah-humbug-say-Mexicans-about-Cinco-de-Mayo)