Using Chrome OS
Wow, they weren't kidding about the boot time. Chrome OS responds (to suspend / resume and boot / power-off) very quickly. Responsiveness elsewhere in the OS of course varies on system load and other factors. On the "terms" page, there is a "system security setting" which tells me I have a Trusted Platform Module, and that my TPM has a randomly generated password. The dialog could use some rewording; I'm pretty familiar with the idea of a TPM, but I'm still not sure what I'm to do with that information.
Cloud print is really a problem for me, right now. I use school printers for the majority of my work, which I was previously able to use by adding them by IP address. Unless there's some magic I'm missing here, I can't do that with Chrome OS, and such a feature will not be supported. (except by "connectors" on Windows and Mac computers)
I can't imagine using a system running Chrome OS as a primary computer. The biggest missing feature is PGP (or any sort of encryption) support for email. This is probably not terribly difficult to implement as an extension, but the idea of my cryptographic software being automatically updated is rather unsettling. I think I'll have to agree with Paul Buchheit that ChromeOS will have to merge with Android; there is a utility for local apps, even if they're becoming less and less critical.