We lived in farms, then we lived in cities, and now we're gonna live on the internet! - Sean Parker/The Social Network
On the elegant but minimalist Chrome OS website, it says Chrome OS is for people who live on the web. To check if you are a native of the web, take their fun quiz which is more of an ad for their products.
One of the Chrome OSs touted benefits is that all your apps, documents, and settings are stored safely in the cloud. The downside I see to this centralized approach is the criticality of protecting your account credentials so that you are not lost in the cloud.