Today's Beta release fixes all that. Signing in to Chrome enables sync and brings your Chrome bookmarks and other personalized settings to all of your computers. Anything you update on one device instantly updates everywhere else.
By adding a "New User" to the Personal Stuff tab of Chrome, a fresh instance of Chrome will open, ready to be customized with a your set of apps, bookmarks, extensions, and other settings. A badge in the upper corner lets you know at a glance that this new Chrome browser belongs to youe. Clicking this badge drops down a menu of all the users on that computer. In addition, you can sign in to Chrome to access their own personalized Chrome across all their computers.
Google says that feature isn't intended to secure your data against other people using your computer, since all it takes is a couple of clicks to switch between users.