While Western Digital also faces significant hurdles in trying to rationalize a significant overlap in HDD products, it gains manufacturing and sales scale -- which in a commodity marketplace can only be a benefit, analysts said. And it gains ground on its chief competitor in the enterprise-class hard drive marketplace, Seagate.

In the fourth quarter of 2010, Seagate had a wide lead over its competition in the enterprise-class arena with 56.2% of the 2.5-in. drive market and 61% of the 3.5-in. drive market, according market research firm IDC. Hitachi GST had the second largest share, with 24.1% and 32.3%, respectively, followed by Fujitsu/Toshiba.

Overall, in that same quarter, Western Digital led the industry with a roughly 31.2% market share, followed closely by Seagate with 29.2% of the market, according to IDC. Hitachi GST was third with 18.1%, and Toshiba and Samsung followed with 10.8% and 10.7%, respectively.

By buying Hitachi GST, Western Digital can also broaden its market reach into Apple Macintosh computers. Hitachi GST is a major supplier to Apple.

According to David Reinsel, the vice president of storage and semiconductor research at IDC, Western Digital stands to gain more than just market share; it'll also get a great deal of intellectual property and manufacturing efficiencies. Currently, Hitachi manufactures most of its drives in China. Western Digital makes most of its drives in Thailand, Malaysia, and Singapore.