That would be very interesting. I wouldn't be surprised to see some merging both directions, and perhaps even soonish... but as it stands today, ChromeOS is barely ready for touch and strongly requires a keyboard for things like Docs, etc to be used effectively. Of course there are bluetooth options, but it feels like we're quite a bit away. It could almost be far enough away that totally new technology changes how we think about what the bridge means.
The issue with Chrome OS on all-touch devices is its touch capabilities (I think it either doesn't have pinch to zoom or it is limited). Having said that, I don't think a keyboard is necessary for Chrome OS to work; what IS necessary is enough horsepower to have a desktop-class browser. When you think about it, the fundamental differences between laptop form factor devices and tablets (and smartphones) besides the obvious UI difference are 1) browser quality (which relates to the processor and operating system demands) and 2) the need for apps. With the first item, the browser quality is one of the primary reasons why a lot of people (including me) like chromebooks better than tablets. With the second item, I'm of the opinion that a laptop form factor device doesn't really need apps (and by apps I mean the apps typically downloaded from a ecosystem's app store); "apps", which are essentially pre-packaged shortcuts, were created because information entry on a touchscreen device is a pain. If Chrome OS can address these three things (touch capability, apps, and browser quality) on a touchscreen device, there's no reason why Google can't create chromepads and chromephones and have an OS that can be used in all device form factor types. (The last of those three items goes back to why chromebooks' ability to function effectively with a "mobile" processor is important; they show a high quality browser can be powered by the kind of processor found in tablets and smartphones.)
In addition to the above, if you think about it you'll realize that in the long-term it makes more sense for Google to focus on Chrome OS rather than Android as their primary operating system. To be frank, Chrome OS functions miles better than Android does (or at least it has based on my user experience.) More importantly Android, like Windows, MacOS, iOS, WP8, and BB 7/10, belongs to the device-based operating system paradigm originated on personal computers in the 1970s. Such operating systems need a high amount of resources to enable continued high performance, and eventually they either need to be replaced or require users to upgrade their devices when the modified operating system is no longer supported on their devices. These limitations aren't good for the consumer, but the consumer will accept them if there aren't better alternatives. By contrast, Chrome OS is a cloud-based operating system where most of the "power" for the device is located on remote servers and the device functions more like a thin client end terminal. Such devices don't have nearly as intensive of resource requirements. More importantly, the operating system updates are performed at the server end, so the updates are both simpler and easier to implement on the device (both from the manufacturers' and users' points of view) and enable the device to function efficiently for a longer period of time. You can't have an effective cloud-based system unless there is a high capacity and reliability communications infrastructure in place. However, that kind of infrastructure is exactly the direction the world is headed as internet-based communications become increasingly common and fast.
Because of the advantages offered by cloud-based operating systems over device-based operating systems (which from the consumer end of things are primarily simplicity, speed, and low cost), I personally think within 10 years cloud-based operating systems will become the norm and device-based operating systems will become the niche, provided the cloud-based operating system requirements are met. This is the exact opposite of what we have today. Google (and to a lesser degree Mozilla with its Firefox OS) is well-positioned with Chrome OS to be a leader in this paradigm shift.