Watch out, Twitter and Facebook. Google is on your heels.

Google is close to adding a new social networking component to Gmail – a move which would edge the search giant further into territory traditionally dominated by Twitter and Facebook. According to the Wall Street Journal, which quotes anonymous sources within the company, Google could have the feature up and running by this week. (Google has declined to comment.)

So what would a social media-enhanced Gmail look like? The platform already comes with a popular chat functionality, where users can post "away messages" and links. Google apparently wants to expand that service to collect status updates from multiple users, which would be streamed in the same way Facebook aggregates content on its news feed.

On the one hand, there's a major integration opportunity here for Google. As Nathania Johnson at Search Engine Watch points out, "directly competing with Facebook or Twitter would probably not be a great idea for Google." Facebook is simply too entrenched. But Google does have the option to open things up with its new social media feature. Gmail users, for instance, might be able to send their status updates or links automatically to Facebook and Twitter.

But others see the impending Google move as nothing less than a direct sally against Twitter and Facebook. At TechFlash, Todd Bishop says that Google is the one company with enough clout to present a viable alternative to Facebook. Maybe. But it would be an uphill battle from the outset: Facebook says it has upward of 400 million unique users. Gmail? 176 million unique users.

Does Google have a shot at knocking Twitter and Facebook off the social networking heap? Are there room for three at the top? We want to hear from you. Drop us a line in the comments section, or follow us on Twitter for more sci-tech news.