Some of Yahoo's most valuable assets might switch to Google Search

Yahoo Japan is one of Yahoo's most valuable assets , but it is not fully owned by Yahoo and is not obligated by Yahoo's recent agreement with Microsoft to use Bing. There are a lot of posts about Google trying to reach an agreement with Yahoo Japan but the best one seems to be this one by Kara Swisher.  If they reach an agreement, Google would essentially control the Japanese search market.

The Alibaba Group owns Yahoo's name in China, and is partially owned by Yahoo. Its currently using Yahoos' search technology, but is also free to switch if it wants to. Yahoo Japan has partnered with Taobao (China's top ecommerce website and a subsidiary of the Alibaba Group) to list over eight million items in a Chinese-language TaoJapan section. That might cause a ripple effect if Yahoo Japan switches.

Yahoo Japan is very different from what somebody in the USA is used to. Its very localized , with what a non-Japanese would consider a very cluttered site. Even Google (in Japan) has customized its sparse splash page and added links to numerous services to try to cater to Japanese users. Yahoo Japan scans passerby's and puts personalized content on billboards . Supposedly the install CD from most Japanese ISPs sets the home page to Yahoo Japan, and few users bother to change it. Cheap 100Mbps residential broadband with a IP phone is also fairly standard. Why Yahoo! is more popular than Google in Japan has some more details.