Starting on November 4th, Google began displaying logos for Sesame Street's 40th anniversary. Today is Sesame Street's official anniversary, the previous logos all led up to today. That is why we have a collage of all the characters, all in one logo:
Yes, 12 Sesame Street personalities in total were displayed. Not all on Google.com, some on regional Googles. Here they all are:
Honestly, I think I may have even missed one. :)
For all those wishing Google give up the Sesame Street logos, I think today is the last day. Personally, I liked it...
Forum discussion at Google Web Search Help.