Sometimes friends really come in handy... Western Digital and Toshiba are trading favours, with WD giving Toshiba the equipment and IP required to make and sell consumer-grade 3.5" HDDs.
In return, Toshiba is giving WD all assets from Toshiba Storage Device (TSDT), including a 2.5" HDD manufacturing facility. TSDT is currently closed down following the 2011 Thailand flood disaster.
Why are the 2 companies going such a barter? Simple-- WD needs to offload part of its 3.5" HDD business in order to satisfy EU conditions before finalising its Hitachi GST (the Hitachi HDD business) purchase.
On the other hand, Toshiba wants to push further in both CE and PC markets with an expanded product portfolio.
With the WD-Hitachi GST purchase complete and Seagate owning the Seagate HDD business, the HDD industry will soon be left a duopoly... unless Toshiba manages to take up the slack.