Touch screens are usually a standard LCD with a touchscreen membrane stuck over the screen. the touchscreen membranes are usually connected via serial (USB these days) and emulate a mouse. So it's perfectly logical for it to connect to the same device (actually 2 devices) using the 2 connectors. Hope that clears it up.
Oh forgot to mention, isn't OS X actually a linux distro? I'm pretty sure that the underlying software in the I wanks, sorry ipads is probably linux based aswell. I'm sure that there are or will be plenty of sites popping up with hacks etc to encourage use of the Pi
Imagine? Plenty of tv's already have stuff like this built in. My Samsung tv has the same ARM11 processor with 256MB or 512MB ram (don't know the exact specs), running linux. It plays HD video from a USB key or LAN and comes with several internet apps like Youtube and Vimeo.
Looks very interesting...will definitely be buying one of those when they become available. I don't have any specific use in mind yet, but it'd be worth it just to play around with.