Age, socioeconomic status, vocations and avocations of potential users? There's large swathes of the planet who don't have access to the internet yet, and Google wants to sell their user data to advertisers when it eventually comes online. There's people like me who want a fire-and-forget computing experience, so that I can choose to tinker with computers and also choose to not care at other times. There's people whose computing experience is web browsing in place of TV browsing a decade ago, for whom the computer in hand doesn't really matter.
I kind-of expect Dell and Microsoft to respond to ChromeOS with a managed-service laptop on some lightweight edition of Windows (perhaps that's what the Windows-on-ARM announcements at CES were about). Outsourcing your duty to care for your equipment is going to become a commodity that you buy; I've spent the last decade with a mobile phone contract where I get next-day replacement of the phone if broken or lost and think that there are many people who would pay to have the same for their personal computing needs.