The magic pad is tipped to give Apple’s Macintosh laptops and Desktop machines the multi touch capability just like you have on the iPad! How cool is that?! From the picture it appears that the device is a peripheral and has a power button. I assume it would connect via Bluetooth or wired. It just shows Apple’s keenness to bring multi-touch capabilities to their relatively under-successful desktops and notebooks.
Frankly speaking, I expect the device to do something more than mere replacement of a mouse with its multi-touch capabilities. There are some rumors that this device supports handwriting recognition in addition to “every feature you can find on a Magic Mouse (and possibly features of a MacBook Pro trackpad).” Now that is something to cheer for! Let us just wait a while for Steve Jobs’ keynote at WWDC and look for some exciting announcements like these!