Cool stuff, you can now enable Google Instant from Search bar in your Chrome browser if you're up to date with the latest Dev build (just updated this morning for me). Just head to about:labs and enable "instant" in the settings there, and then hit the restart button.
It works as expected, filling the browser window with the search results from your typing on the address bar, and clearing it and going back to whatever page it was before if you hit ESC to clear it. Looking forward to how it feels and works in practice. Note: Not only mac, works in all (dev) builds of the browser.