At the end of the day, for Google to succeed, one of Chrome OS's achievements has to be to match a lot of what desktop computing is today. In fact, one "ideal" scenario is for Chrome OS to simply be the same as desktop computing today, except "better". For example, it would be faster (launch more quickly, open apps faster, etc.); the deployment model would be simpler (over the web, no more software updates for apps, etc.); and more secure. However, while these advancements are certainly great, these are all very much simply an evolution of the current desktop model. Most of the "revolutions" in Chrome OS exist for developers, not users.
On the other hand with iPad you have to admit that it is drastically asking you to reanalyze what it means to use a computer. This isn't a value judgment: it remains to be seen whether this new model will be good or intuitive or successful or what have you, but it is different.
And are there any devices with ChromeOS available or about to be available in the next month or two? It was announced months and months ago. Can you write apps specifically targeting it yet? Do you even want to? What kind of device is Google targeting with ChromeOS? Whatever it can fit on? How is a ChromeOS app different from an HTML5 app on the iPad?
I don't even know what Google's intentions with ChromeOS are. At least with Android, theres some sort of direction, even if it does get hijacked and thrown away by other companies. With the iPad, you know what market the OS is aimed at. Not so with ChromeOS or Android, to a lesser degree.