If anyone is interested, Print Preview is going to be available in the stable release of Chrome 13. Its currently available in the dev version for Windows , Linux, and Mac but is full of bugs.
If you are using Chrome 12 (stable) the preview feature can be turned on in Windows, Linux and Mac. Its off by default as its not fully functional in any of those operating systems. If you go into the 'flags' area of Chrome, there is an 'enable ' button.
All you can do is view the preview, none of the other features you typically expect in a Preview window are available.