This sandbox is "as strong" as Chrome's extremely robust native version -- even in Windows XP, which means flash malware attacks *should* not hurt users of supported versions of Windows. Securing the Flash Player plug-in is the result of two years of work, and was made possible by a new plug-in architecture Google co-developed with Adobe. In addition to the security benefits, the architecture has also brought performance improvements by way of a 20 percent decrease in Flash crashes and GPU acceleration for smoother scrolling and faster Flash rendering.
If you are on Linux, Chrome 20 already put flash into a sandbox for you, that might have flown under the radar for most Linux users.
If you are a user of Mac, sand boxing is coming, according the Chrome blog. As always, let me know of your thoughts below.
Source: Google Chrome Blog