Gmail is set to become Google’s next major push into social media. According to The Wall Street Journal, the popular webmail service will soon launch a new feature for sharing content and status updates with friends. [Update: We think Google might announce these features on Tuesday]

As WSJ points out, Gmail users can already update their statuses — sort of — through Gmail’s chat feature. Currently, this feature is more akin to the traditional IM “away message.” However, with this new social push, Gmail will offer a timeline-view of your friends’ status updates, just like on Facebook and Twitter.

Those updates might come from both Gmail and third-party services. According to WSJ, Google-owned YouTube and Picasa will be integrated into the stream. The huge question then is whether or not the new feature will include updates from Twitter and Facebook.

If so, the new features could be thought of more like a TweetDeck or Seesmic, looking to provide an aggregate view of your friends’ social media activities along with the ability to push status updates to the services you use from inside of Gmail. If not, it could be thought of as a major competitor to Twitter and Facebook as Gmail looks to covert its millions of e-mail users into adherents to a whole new breed of social media service.

An issue with the latter, however, is that Gmail has historically added people to your contacts based on e-mail interactions. Hence, this contact list often varies significantly from your friends on social sites where relationships need to be made explicitly.

In other words, your Gmail contacts aren’t necessarily the same people you want to share status updates, photos and videos with. This is an issue that shouldn’t be overlooked in evaluating the new features Google is soon to unveil.