It's official. Sony and Toshiba just issued a press release saying that the two companies have signed a binding memorandum of understanding to transfer Tosh's fabrication facilities, operated by Nagasaki Semiconductor Manufacturing, back to Sony. A deal that is rumored to cost Sony some 50 billion yen (about $835 million) -- a bargain considering that Sony sold the facilities that manufacture the Cell Broadband Engine, RSX graphics engine, and other SoCs to Toshiba for 90 billion Yen back in 2008. Unfortunately, Sony's being coy about its plans for the new facilities. The two hope to complete the transfer sometime in the fiscal year ending March 31, 2012.