Google software engineer Gary Kačmarčík revealed Chrome OS will offer support for Windows applications via a process called "Chromoting". Little is known about the feature, but PC Mag speculates it's likely to be a VPN/sharing functionality, that enables you to access software on your Windows PC via Chrome OS' browser.
"We're adding new capabilities all the time. With this functionality (unofficially named "chromoting"), Chrome OS will not only be great platform for running modern web apps, but will also enable you to access legacy PC applications right within the browser," wrote Kačmarčík. "We'll have more details to share on chromoting in the coming month."
The current speculation amongst Chrome enthusiasts is that the Chromoting process is more akin to a VPN/sharing functionality than anything else. In that case, one would have to leave one's Windows-based desktop or laptop system on in order to access apps via a connected Chrome OS computer—which, itself, is hardly a technological leap given that numerous applications today offer users an analogous screen-sharing / remote access functionality.