Admittedly, DX11.1 offers only incremental upgrades from DirectX 11. But many of those features promise greater efficiencies in the Direct3D pipeline (bigger constant buffers, for example). DirectX 11.1 also adds stereoscopic 3D support. For Windows 8, the key feature that DirectX 11.1 brings to the table is better 2D performance through Direct2D, which means that windows pop onto the screen more fluidly, and overall text rendering is much snappier.
Keyboard, mice, and touchpads
Windows 8 supports touch and gesture recognition in a big way. Nevertheless, though you may be tempted to upgrade to a multitouch desktop display, only a handful of models are available on the market today--and the ones that do exist are either quite expensive or painfully small. But some nifty touch-enabled interface devices are available (or are coming very soon), and they have the potential to work more effectively with Windows 8.
For example, Microsoft has released its Touch Mouse, which works like a normal mouse, but has a touch-sensitive surface that will support Windows 8 multitouch gestures. The Wedge Touch Mouse is similarly touch-sensitive, but it's tiny and portable. Since the Wedge Touch works with Bluetooth, it is ready for the coming generation of Windows 8 tablets.
Logitech's 5-inch wireless touchpad fully supports multitouch gestures, and should work with Windows 8 gesture recognition. Large touch surfaces have the potential to emulate the way touch displays work, and can serve as a viable substitute.
On the speculative side, I'd love to see a touch-enabled mousepad, but designers must overcome some obvious technical challenges first, such giving the mousepad the ability to detect when the user is wielding it as a mouse and when the user is employing multiple finger gestures.
Buying a new PC: What you want for Windows 8
Your laptop died. Your desktop PC is on its last legs, as the tell-take grinding sound of the hard drive indicates. How do you proceed if you have no alternative but to buy a new PC today? The relevant considerations differ, depending on whether you need a laptop or a desktop.