Hope Unity Web Player will work with this 
Considering that Web Player doesn’t work with regular flavors of Linux, I see no reason for it to work with this one. However, considering that there’s also a fair amount of demand for Linux support in web players I see no reason why it shouldn’t eventually be supported in the future. 
If it works with Chrome on Linux chances are there it could work with that.
What though works against it is that Google likely will not put a massive effort on 3D graphics drivers … meaning that you are at worst back at the point where you have to compile them yourself, because Chrome OS is targeted to be a web os for netbooks and alike, not a fullscale OS (the bootup video shows you how much of the regular OS stuff they just jump because their environment does not need it)
Ive read somewhere that a Mac version is very close to launch.
From what i can see, for now its just a browser with an additional feature of two, nothing spectacular. So no wonder it loads in 7 seconds. Still a long way to go.
Whole OS based on tabs, though? Im… not too sure about that idea…
Yes Unity Tech would have to make a Linux web player for Chrome browser.
Because you can’t install any software on Chrome OS
but Chrome browser plugin’s will work (unity web player / flash and so on)