When did facebook become such an over achiever?

Let's be clear, I've always liked facebook. They achieved what at one point seemed impossible, they made a social network and somehow got everyone on it. My best friend's mom, yeah she's there. She updates regularly too. For people my age (college students) a facebook account is all but assumed. However I never considered the facebook team to be whiz-bang programmers. Admittedly what they're doing is hard, and they're always setting the watermark for scale. When facebook originally came out I thought: "brilliant, no asking people for their screen names, people are almost always online, this should be the last IM service I need for a long time..." nope. Nothing worked it mysteriously disconnected, it dropped so many messages that I started sending ACKs. But I still used it, because I have 120 email contacts only a small subset of them have chat but I have around 500 fbriends. That's too many people for whom facebook is my only line of contact not to use it. However I always knew that this was also the reason that facebook didn't need to improve, until recently they had my usership simply by virtue of their ubiquity, however it only took the slightest indication that someone (who goes by the name twitter) might be about to eat their food and suddenly facebook is dropping slam dunks, they just released a new chat today and it's beautiful it let's you go offline on a per fbriend list basis (I just setup an ex-girlfriend list). I don't think gChat even has that, if they do it's clearly not as intuitive as facebook's. And furthermore facebook created their own standards, no conformity for them. Hats off.