FYI, Les Paul, Martha Graham, Earth Day, World's Fair, and Yuri Gagarin are all up now:

http://www.google.com/logos/2011/lespaul.html

http://www.google.com/logos/2011/graham.html

http://www.google.com/logos/2011/worldsfair.html

http://www.google.com/logos/2011/earthday.html

http://www.google.com/logos/2011/space.html