Asus’ dual-boot Transformer Book Duet is dead. At CES this year, one of the big stories was dual-OS devices. Spurred on by encouragement from chipmaker Intel, Asus announced the Transformer Book Duet, a hybrid laptop and tablet that switches between Microsoft Windows and Google’s Android on the fly. The device was an intriguing highlight at a trade show that was generally devoid of interesting laptops and tablets, and was scheduled for release in the US this month.