Hell yes I put it up on facebook. There's no way I would have been able to tell all my friends individually (I waited about a week though so I could tell all of my closest friends/family). So updating status makes it a lot easier. Plus, it is one of the milestones in your life.. don't you want to share it with people? I think it's a bit over the top to avoid putting it up in order to prevent other people from being jealous..
When I've had people, even ones that I wasn't close to, post updates about getting accepted to med school -- I congratulated them. They just did something really awesome, and I'm not gonna let my own insecurity get in the way of celebrating their victory.