PC gamers will recognize Battlefield 3's Battlelog as the browser-based service you have to load before you can play the game. As this trailer explains, there's more to Battlelog than a server browser and front end. Battlelog expands on the franchise's history of stats tracking, melding it with new social networking features that look like they've been ripped right out of Facebook.
I have a friend who was mildly obsessed with his Battlefield 2 rank, so I understand the interest in tracking one's performance in the game. Indeed, our own Cyril Kowaliski is guilty of showing off "battle reports" from the beta. You probably don't want to share those reports with the entirety of your Facebook friends list, so keeping them within the game's framework makes a lot of sense.
Battlefield has long encouraged teamwork, and it looks like Battlelog's social networking component will make it easier to not only play with your friends, but also track each others' progress in the game. Online multiplayer games tend to be much more enjoyable when you're playing with friends rather than strangers, so despite my general disdain for social networking, I have to admit to being intrigued by Battlelog—not that I'll be able to avoid it.