It will be great for those longer trips where your iphone just isnt nice enough, yet your laptop is too much of a burden. You know when you want to carry a bag, but not that heavy of a bag. When you want a bigger screen then your phone, but still want to hold the device in your hands. When having a keyboard is a hassle. It will also make wearing a purse more socially acceptable; "its for my Ipad".
So I think its necessary for gay or "europeon" men, and women who like using purses/satchels; while they take their 30+min commute by train, 3+ times a week.