How to make Chrome open a new window for external Links
You can try using the AppleScript found on this page.

I just tried it out and it perfectly works fine in Chrome 12.0.742.122.

It's extremely easy to set up:


download the Bundle archive
double click it to unpack it
double click on OpenUrlInNewChromeWindow
open Safari and set the new "Browser" as the default browser in the Preferences.