I imagine they will be incorporating their current and in-development webapps-becoming-more-like-desktop-apps features, such as the background feature:
http://blog.chromium.org/2011/02/amping-up-chromes-background-feature.html
"Apps and extensions that use the new “background” feature can continue to run in the background—even if the user closes down all of Chrome’s windows. “Background apps” will continue to run until Chrome exits. The next time Chrome starts up, any background windows that were previously running will also be re-launched. These windows are not going to be visible but they will be able to perform tasks like checking for server-side changes and pre-emptively loading content into local storage."