Following over a year of speculation, Google has launched Google Now for its alpha version of Chrome, Canary. As suspected, Google Now integrates with the browser's notification center, pulling in weather, sports, travel, and other information. The functionality found in the desktop Google Now isn't identical to the mobile versions; some Cards are missing including one the shows stock market information, but it's likely Google will flesh out the service before bringing it to the masses.
The service is not switched on by default and, as Google Operating System reports, requires you to enable a flag in Chrome settings. Features debuted in the Canary build of Chrome can often take months to make their way to the regular version, but Google already has a support page ready for a full rollout. If you're interested in giving it a spin, you can download Chrome Canary here. Canary is intended for developers and, as Google says, "can sometimes break down completely," so it's not recommended for daily use.