If you want to enable it, all Chrome builds (including the stable build) will let you add the flag --enable-aero-peek-tabs after the quoted path in the shortcut on your desktop or in your taskbar (if you hold shift when you right click you can go to properties and add it there).

If you go to start Chrome and realize it didn't work, close down the browser and make sure you end all Chrome.exe processes in the task manager. Certain plug ins are more persistent than the actual browser and will retain chrome's settings (such as this one) until the entire browser restarts (at least in the dev version, to which this is not exclusive).