The other two similar homepages are for Google Korea (launched on June 12, 2007) and Google Japan (launched on March 21, 2008). Google China Blog says that the three homepages were a part of bigger project meant to improve Google's interface and to adapt it to local cultures. For example, Chinese users found it difficult to navigate to other Google services, since they were listed on a different page, so Google decided to place the links more prominently on the homepage.
I liked the last paragraph from Google China's blog post (or its automatic translation, to be more exact):
The change in the Asian region in the entire Home Google is a major patron saint Google Home Marissa has given us the greatest help, and this was her first "replacement" Movement biggest supporters: "You can change as much as possible "of this so let us encourage the Google home page of this classic too bold move from the surgery. Google Home is not static, but, as she insisted to the interests of users, she is also due to the change and you change.
Google already provides an alternative to the "classic" homepage: iGoogle, but the default homepage hasn't changed too much over the years.
{ via Zorgloob }