4.2.2 on board.And, when we say the Trio is a mashup of the Transformer Book and the Transformer Pad, we mean it. The Trio tablet features an 11.6-inch 1080p display, and is powered by an Intel Atom Z2760 1.6GHz processor and 2GB of RAM. You'll get the choice of either 16GB, 32GB, or 64GB of storage. The tablet side of course has Android
The keyboard dock is where you'll find the power for the Windows 8 side of things. For that, you'll get a choice of processor up to an Intel Core i7 Haswell chip, 4GB of RAM, and up to 1TB of storage. ASUS is saying you'll get up to 13 hours of battery running Android (with the keyboard dock), but just 5 hours running Windows 8, despite the Haswell chipset.
One interesting thing is that the keyboard dock can be hooked up to an external display and used independently of the tablet display. Although, it sounds like your only option with the tablet will be Android, and you won't be able to use the display as a Windows tablet.
Again, no word on pricing or availability.