A week after rumors surfaced about Facebook’s acquisition of New York-based check-in-to-everything service Hot Potato, CNET’s Caroline McCarthy reports that the company’s long-awaited plan to enter the geolocation check-in space may finally be at hand. At a time when the social network is supposedly in lock-down mode, bracing for battle with Google’s supposed Facebook-killer, the debut of geolocation could give it an interesting edge.

While specific details about the social network’s plans in the space are still speculative, McCarthy’s sources say it might be integrating existing check-in startups through their respective APIs in an effort to make location a key part of the service — effectively creating what GigaOm is calling ‘Facebook Places.’

What remains unknown is to what extent this integration will rely on third-party services like Foursquare, Gowalla, and Loopt, and whether Facebook has plans to add its own check-in function. Given its rumored acquisition of check-in service Hot Potato last week, it seems to be headed in the latter direction. GigaOm points to Facebook’s recent blog post on its privacy policy changes, where the company mentions originally thinking of location as just a way to “add a location to something you post.” But now, it seems to have broadened its thinking.

Despite all the hee-hawing, the marriage of location and Facebook seems to be inevitable. Most location services today are used for their check-in features, and to a lesser extent to sift through friends’ activity, which is where their real utility lies. On the other hand, Facebook’s NewsFeed serves as the perfect hub for aggregating data about ones’ friends, one which has so far been lacking location. It’s logical to anticipate future NewsFeed updates taking the form of “John Doe is at AMC Van Ness on Van Ness Avenue, San Francisco.”

But for startups like Foursquare and Gowalla, it is Facebook’s approach to location that could either make the social network a friend or foe. If simple API integration is what the company guns for, then it could give the bevy of location startups access to 500 million users and a chance to have their check-ins be more useful than they are today. That said, if Facebook introduces its own check-in service, the companies and investors that have been dominating geolocation to date may be in trouble.

Facebook has been contacted for a comment.