Google launched 3D street views on Google Maps on April 1, 2010. Many thought it was an April Fools day prank when it was dropped. But then Google said they may bring it back and it seems they did indeed bring it back.
The 3D street views man is gone, but if you right click on a street views image, you will have the option to turn "3D mode on." Here is a picture of 3D mode on:
I am glad it is back, since so many people purchased 3D glasses and had nothing to do with them (I am serious).
Forum discussion at Google Blogoscoped and Google Maps Help and hat tip to Websonic.