A single Apple ID linked to the account that allows access to photos, social websites, sensitive document, browsing history, email access. Sounds like personal usage to me.
You think isn't the same as they are. What you think could prove to be very incorrect.
In fact I think it is. I think they have been and will continue to position the iDevices as essentially single user, although they might add the saved restrictions profiles type idea that my cousin suggested (same cousin linked in my sig)
Well by all means knock yourself out with watching the 1 hr and 58 min Keynote videos Apple's website if you want to see if it may be included in iOS 7.