Also, the cloud dependency means, at least right now, you can't launch an "installed" application when disconnected. The app on your home screen is just a link to the app on a Web server somewhere. If you're not at home or at an office with a good Wi-Fi network, that means you'll never be sure if you can launch an app. After all, 3G service is spotty and inconsistent: Even within a fixed location such as a home, you may get a signal in one location but not another, and certainly if you commute by train or bus you know that the 3G signal comes and goes. To address this issue, maybe Google will use HTML5's offline storage capacity to keep "installed" applications locally cached, not just their data, so you can launch them at any time. We'll see.
In using Chrome OS over both Wi-Fi and Verizon 3G service (which is slow to reconnect after you've been idle or put the Chromebook asleep), I frequently noted the slowdowns as applications and documents loaded. That didn't bother me for the InfoWorld CMS, which is a Web app whose pauses I'm already used to. But it was disconcerting in Office Web Apps and Google Docs compared to using a local app such as Microsoft Office or Apple iWork. I'll probably get used to the pauses, but for now it triggers fear that I'll lose my data because of a connectivity snafu -- not a worry about when using my MacBook Pro or iPad, as they can always save locally.
At this point, there aren't any serious Chrome apps to explore how far you can go with Web apps. I'll do a follow-up report when there are.
Using the ChromebookThe all-black, unlabeled Cr-48 laptop that Google has provided for beta testers is definitely not something you'd want to buy. It's a cheap system whose keyboard is a bit imprecise and thus typo-prone, and whose trackpad is intermittently unresponsive and subject to random selection and cursor movements (known bugs at the Chrome OS help site). But Google was clear the Cr-48 is not a production-quality device. Acer, Samsung, and perhaps others will make the real thing, and they'll likely have better quality.
However, the prototype Chromebook does demonstrate the assumptions Google has for real models. Basically, they're small laptops, with 12-inch screens and no hard drves or optical drives, so they weigh only about 4 pounds. The 12-inch screen felt tight to me, even after I upped the default font size by 25% -- a 13-inch screen would be better for my middle-aged eyes.