It's a strange world where this is the case, but Windows 7 is a lot more open than either ChromeOS or the iPad.7. hromeOS is similar to the iPad in that you're limited in your ability to install the software of your choice - does it even have native programs that you can install?. Isn't that like the complaint so many of us have about the iPad, that it doesn't have a full featured OS?
No, the complaint is that you can't do anything on the iPad that Apple doesn't want you to do. I'm decently sure that you can get to a command line in Chrome OS (not sure if that'd be in the final version), and Google doesn't really go for the whole "only Google" mentality (the only Android device that explicitly disallows non-Market apps is the Motorola Backflip)
Sure, it's not as closed as Apple's systems. However, it's still not a real computer. I want a tablet that is just a laptop running a normal OS, with accommodations for a touch screen. There's no indication a ChromeOS tablet will be anything like that.