Err, why would they? I don't envision any high speed data transfers occurring on a regular basis, or really anything but a phone or a keyboard being plugged in.
Because its available and better and this is being marketed as a premium device. Since you mentioned phones though I remember reading that 3.0 could enable faster charging than 2.0. Also, with the 1TB of cloud space, I would probably want to copy something off there from time to time and would like the faster speeds.
What about a camera? Or backup hard-drive? Heck, I rarely use online backup services for my photos since the files are so ridiculously large so I just end up using multiple HDDs.
