After Partnering with Bing Yahoo is now concentrating more on things they are good at. i.e. Portals.
"This acquisition will accelerate Yahoo!'s strategy of expanding in high-growth emerging markets where we believe Yahoo! has unparalleled opportunity to become the destination of choice for consumers," said Yahoo! chief executive officer Carol Bartz. "Access to information and communications tools can positively impact people's lives in many ways, and with the acquisition of Maktoob.com and our investment in the region, the Arab world will soon get a Yahoo! experience in Arabic with relevant local language content, programming and services."
Check the official news here